53 results on '"Wenyan Zhang"'
Search Results
2. A COMPARATIVE STUDY ON TWO METHODS OF DECOUPLING A SIX-AXIS ACCELEROMETER WITHOUT AND WITH A GYROSCOPE.
- Author
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Chenggang Li, Wenyan Zhang, Jing Chen, and Jingjing You
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GYROSCOPES , *ACCELEROMETERS , *COMPARATIVE studies - Abstract
Methods of decoupling a 6-axis accelerometer are attracting more and more attention because of their great significance for the accuracy, efficiency and stability of acceleration calculation. This paper introduces the basic decoupling methods without and with a gyroscope first. The decoupling accuracies of numerical accelerations are compared based on the definition of the comprehensive error, and the efficiencies are compared based on the computational time. In order to compare the stability of the two methods, the influence of step size is given, and the comprehensive errors are compared. Possible error sources that affect the stability of the decoupling methods are listed and divided into three categories, and the influence of every error source is analysed and presented. In the simulation, the gyroscope-based method is verified to achieve better accuracy, efficiency and stability than in the case of the method without a gyroscope. The experimental results agree well with the theoretical analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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3. Efficacy of liver cancer microwave ablation through ultrasonic image guidance under deep migration feature algorithm.
- Author
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Changkong Ye, Wenyan Zhang, Zijuan Pang, and Wei Wang
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LIVER cancer , *ULTRASONIC imaging , *CATHETER ablation , *ALGORITHMS , *DIAGNOSTIC ultrasonic imaging , *CONVOLUTIONAL neural networks - Abstract
Objective: To explore the therapeutic effects of ultrasound-guided microwave ablation and radio frequency ablation for liver cancer patients. Methods: Seventy-eight patients with microwave ablation were rolled into the experimental group and 56 patients with radio frequency ablation were in the control group. This study was conducted from March 1, 2019 to June 30, 2020 in our hospital. Based on Convolutional Neural Networks (CNN) and Migration feature (MF), a new ultrasound image diagnosis algorithm CNNMF was constructed, which was compared with AdaBoost and PCA-BP based on Principal component analysis (PCA) and back propagation (BP), and the accuracy (Acc), specificity (Spe), sensitivity (Sen), and F1 values of the three algorithms were calculated. Then, the CNNMF algorithm was applied to the ultrasonic image diagnosis of the two patients, and the postoperative ablation points, complications and ablation time were recorded. Results: The Acc (96.31%), Spe (89.07%), Sen (91.26%), and F1 value (0.79%) of the CNNMF algorithm were obviously larger than the AdaBoost and the PCA-BP algorithms (P<0.05); in contrast with the control group. The number of ablation points in the experimental group was obviously larger, and the ablation time was obviously shorter (P<0.05); the experimental group had one case of liver abscess and two cases of wound pain after surgery, which were both obviously less than the control group (four cases; five cases) (P<0.05). Conclusion: In contrast with traditional algorithms, the CNNMF algorithm has better diagnostic performance for liver cancer ultrasound images. In contrast with radio frequency ablation, microwave ablation has better ablation effects for liver cancer tumors, and can reduce the incidence of postoperative complications in patients, which is safe and feasible. [ABSTRACT FROM AUTHOR]
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- 2021
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4. A Preliminary Research Study on the Library Collections and Services of Public Primary and Middle Schools in Guangzhou, China.
- Author
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Wenyan Zhang, Hui Wang, Mengmeng Ji, and Sheng Xu
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LIBRARY materials , *PRIMARY schools , *MIDDLE schools , *LIBRARY science , *SCHOOL libraries - Abstract
Primary and middle school libraries are able to play an important part in the development of librarianship in various countries. They help to develop reading and information skills and lay the foundation for a future information literate citizenry. While China has achieved much progress, its school libraries have not been studied from the perspective of school characteristics. This study used a survey approach to examine the collections and services of school libraries in the city of Guangzhou, China. Based on the responses to 133 questions, it was found that the collections and services varied significantly according to the types of schools, the locations, the boarding conditions, and the schools' running subjects with the first three factors contributing more significantly to the variations. It was found that, generally, primary schools and non-boarding schools have the weakest collections and services. This study, although based on a small sample, shows that Chinese school libraries are in need of much development. It is hoped that the findings will lead Chinese scholars, policy-makers, and administrators to put more effort and resources into school library development. [ABSTRACT FROM AUTHOR]
- Published
- 2016
5. Cellular Requirements for Bovine Immunodeficiency Virus Vif- Mediated Inactivation of Bovine APOBEC3 Proteins.
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Wenyan Zhang, Hong Wang, Zhaolong Li, Xin Liu, Guanchen Liu, Harris, Reuben S., and Xiao-Fang Yu
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RETROVIRUSES , *SIMIAN immunodeficiency virus , *UBIQUITIN ligases , *VIRUS diseases , *RNA interference - Abstract
Human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) viral infectivity factor (Vif) form a CRL5 E3 ubiquitin ligase complex to suppress virus restriction by host APOBEC3 (A3) proteins. The primate lentiviral Vif complex is composed of the unique cofactor core binding factor (CBF-β) and canonical ligase components Cullin 5 (CUL5), Elongin B/C (ELOB/C), and RBX2. However, the mechanism by which the Vif protein of the related lentivirus bovine immunodeficiency virus (BIV) overcomes its host A3 proteins is less clear. In this study, we show that BIV Vif interacts with Cullin 2 (CUL2), ELOB/C, and RBX1, but not with CBF-β or CUL5, to form a CRL2 E3 ubiquitin ligase and degrade the restrictive bovine A3 proteins (A3Z2Z3 and A3Z3). RNA interference-mediated knockdown of ELOB or CUL2 inhibited BIV Vif-mediated degradation of these A3 proteins, whereas knockdown of CUL5 or CBF-β did not. BIV Vif with mutations in the BC box (Vif SLQAAA) or putative VHL box (Vif YI-AA), which cannot interact with ELOB/C or CUL2, respectively, lost the ability to counteract bovine A3 proteins. Moreover, CUL2 and UBE2M dominant negative mutants competitively inhibited the BIV Vif-mediated degradation mechanism. Thus, although the general strategy for inhibiting A3 proteins is conserved between HIV-1/SIV and BIV, the precise mechanisms can differ substantially, with only the HIV-1/SIV Vif proteins requiring CBF-β as a cofactor, HIV-1/SIV Vif using CUL5-RBX2, and BIV Vif using CUL2-RBX1. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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6. Existence and Well-Posedness for Symmetric Vector Quasi-Equilibrium Problems.
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Kaihong Wang, Wenyan Zhang, and Min Fang
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QUASI-equilibrium , *EQUILIBRIUM , *MATHEMATICAL optimization , *VARIATIONAL inequalities (Mathematics) , *FUNCTIONALS , *HAUSDORFF spaces , *NUMERICAL analysis , *MATHEMATICAL models - Abstract
An existence result for the solution set of symmetric vector quasi-equilibrium problems that allows for discontinuities is obtained. Moreover, sufficient conditions for the generalized Levitin-Polyak well-posedness of symmetric vector quasi-equilibrium problems are established. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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7. Development of a modelling methodology for simulation of long-term morphological evolution of the southern Baltic coast.
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Wenyan Zhang, Harff, Jan, Schneider, Ralf, and Chaoyu Wu
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BARRIER islands , *WINDS , *TIDAL currents , *COASTS - Abstract
The Darss-Zingst peninsula at the southern Baltic Sea is a typical wave-dominated barrier island system which includes an outer barrier island and an inner lagoon. The formation of the Darss-Zingst peninsula dates back to the Littorina Transgression onset about 8,000 cal BP. It originated from several discrete islands, has been reshaped by littoral currents, wind-induced waves during the last 8,000 years and evolved into a complex barrier island system as today; thus, it may serve as an example to study the coastal evolution under long-term climate change. A methodology for developing a long-term (decadal-to-centennial) process-based morphodynamic model for the southern Baltic coastal environment is presented here. The methodology consists of two main components: (1) a preliminary analysis of the key processes driving the morphological evolution of the study area based on statistical analysis of meteorological data and sensitivity studies; (2) a multi-scale high-resolution process-based model. The process-based model is structured into eight main modules. The two-dimensional vertically integrated circulation module, the wave module, the bottom boundary layer module, the sediment transport module, the cliff erosion module and the nearshore storm module are real-time calculation modules which aim at solving the short-term processes. A bathymetry update module and a long-term control function set, in which the 'reduction' concepts and technique for morphological update acceleration are implemented, are integrated to up-scale the effects of short-term processes to a decadal-to-centennial scale. A series of multi-scale modelling strategies are implemented in the application of the model to the research area. Successful hindcast of the coastline change of the Darss-Zingst peninsula for the last 300 years validates the modelling methodology. Model results indicate that the coastline change of the Darss-Zingst peninsula is dominated by mechanisms acting on different time scales. The coastlines of Darss and the island of Hiddensee are mainly reshaped by long-term effects of waves and longshore currents, while the coastline change of the Zingst peninsula is due to a combination of long-term effects of waves and short-term effects caused by wind storms. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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8. AMR1, an Arabidopsis Gene That Coordinately and Negatively Regulates the Mannose/L-Galactose Ascorbic Acid Biosynthetic Pathway.
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Wenyan Zhang, Lorence, Argelia, Gruszewski, Hope A., Chevone, Boris I., and Nessler, Craig L.
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VITAMIN C , *BIOSYNTHESIS , *MANNOSE , *INOSITOL , *ARABIDOPSIS thaliana , *GENETIC regulation - Abstract
Ascorbic acid (AsA) biosynthesis in plants occurs through a complex, interconnected network with mannose (Man), myoinQsitol, and galacturonic acid as principal entry points. Regulation within and between pathways in the network is largely ancharacterized. A gene that regulates the Man/L-galactose (L-Gal) AsA pathway, AMR1 (for ascorbic acid mannose pathway regulator 1), was identified in an activation-tagged Arabidopsis (Arabidopsis thaliana) ozone-sensitive mutant that had 60% less leaf AsA than wild-type plants. In contrast, two independent T-DNA knockout lines disrupting AMR1 accumulated 2- to 3-fold greater foliar AsA and were more ozone tolerant than wild-type controls. Real-time reverse transcription-polymerase chain reaction analysis of steady-state transcripts of genes involved in AsA biosynthesis showed that AMR1. negatively affected the expression of GDP-Man pyrophosphorylase, GDP-L-Gal phosphorylase, L-Gal-1-phosphate phosphatase, GDP-Man-3 ,5 - epimerase, L-Gal dehydrogenase, and L-galactono-1,4-lactone dehydrogenase, early and late enzymes of the Man/L-Gal pathway to AsA. AMR1 expression appears to be developmentally and environmentally controlled. As leaves aged, AMR1 transcripts accumulated with a concomitant decrease in AsA. AMR1 transcripts also decreased with increased light intensity. Thus, AMR1 appears to play an important role in modulating AsA levels in Arabidopsis by regulating the expression of major pathway genes in response to developmental and environmental cues. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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9. Distinct Determinants in HIV-1 Vif and Human APOBEC3 Proteins Are Required for the Suppression of Diverse Host Anti-Viral Proteins.
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Wenyan Zhang, Gongying Chen, Niewiadomska, Anna Maria, Rongzhen Xu, and Xiao-Fang Yu
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DETERMINANTS (Mathematics) , *CYTIDINE diphosphate choline , *CHEMICAL inhibitors , *RETROVIRUSES , *UBIQUITIN , *HIV , *POLYPEPTIDES , *MAMMALS , *TRANSCRIPTION factors - Abstract
Background: APOBEC3G (A3G) and related cytidine deaminases of the APOBEC3 family of proteins are potent inhibitors of many retroviruses, including HIV-1. Formation of infectious HIV-1 requires the suppression of multiple cytidine deaminases by Vif. HIV-1 Vif suppresses various APOBEC3 proteins through the common mechanism of recruiting the Cullin5-ElonginBElonginC E3 ubiquitin ligase to induce target protein polyubiquitination and proteasome-mediated degradation. The domains in Vif and various APOBEC3 proteins required for APOBEC3 recognition and degradation have not been fully characterized. Methods and Findings: In the present study, we have demonstrated that the regions of APOBEC3F (A3F) that are required for its HIV-1-mediated binding and degradation are distinct from those reported for A3G. We found that the C-terminal cytidine deaminase domain (C-CDD) of A3F alone is sufficient for its interaction with HIV-1 Vif and its Vif-mediated degradation. We also observed that the domains of HIV-1 Vif that are uniquely required for its functional interaction with full-length A3F are also required for the degradation of the C-CDD of A3F; in contrast, those Vif domains that are uniquely required for functional interaction with A3G are not required for the degradation of the C-CDD of A3F. Interestingly, the HIV- 1 Vif domains required for the degradation of A3F are also required for the degradation of A3C and A3DE. On the other hand, the Vif domains uniquely required for the degradation of A3G are dispensable for the degradation of cytidine deaminases A3C and A3DE. Conclusions: Our data suggest that distinct regions of A3F and A3G are targeted by HIV-1 Vif molecules. However, HIV-1 Vif suppresses A3F, A3C, and A3DE through similar recognition determinants, which are conserved among Vif molecules from diverse HIV-1 strains. Mapping these determinants may be useful for the design of novel anti-HIV inhibitors. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
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10. Conserved and non-conserved features of HIV-1 and SIVagm Vif mediated suppression of APOBEC3 cytidine deaminases.
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Wenyan Zhang, Michael Huang, Tao Wang, Lindi Tan, Chunjuan Tian, Xianghui Yu, Wei Kong, and Xiao-Fang Yu
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HIV infections , *UBIQUITIN , *MOLECULES , *GENETIC mutation , *PROTEINS - Abstract
Human cytidine deaminase APOBEC3C (A3C) acts as a potent inhibitor of SIVagm and can be regulated by both HIV-1 and SIVagm Vif. The mechanism by which Vif suppresses A3C is unknown. In the present study, we demonstrate that both HIV-1 and SIVagm Vif can act in a proteasome-dependent manner to overcome A3C. SIVagm Vif requires the Cullin5-ElonginB-ElonginC E3 ubiquitin ligase for the degradation of A3C as well as the suppression of its antiviral activity. Mutation of a residue critical for the species-specific recognition of human or monkey A3G by HIV-1 Vif or SIVagm Vif in A3C had little effect on HIV-1 or SIVagm Vif-mediated degradation of A3C. Although the amino-terminal region of A3G was not important for Vif-mediated degradation, the corresponding region in A3C was critical. A3C mutants that were competent for Vif binding but resistant to Vif-mediated degradation were identified. These data suggest that primate lentiviral Vif molecules have evolved to recognize multiple host APOBEC3 proteins through distinct mechanisms. However, Cul5-E3 ubiquitin ligase appears to be a common pathway hijacked by HIV-1 and SIV Vif to defeat APOBEC3 proteins. Furthermore, Vif and APOBEC3 binding is not sufficient for target protein degradation indicating an important but uncharacterized Vif function. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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11. An Arabidopsis Purple Acid Phosphatase with Phytase Activity Increases Foliar Ascorbate.
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Wenyan Zhang, Gruszewski, Hope A., Chevone, Boris I., and Nessler, Craig L.
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ANTIOXIDANTS , *PLANT cells & tissues , *ARABIDOPSIS thaliana , *PHOSPHATASES , *GENE expression , *CRYPTOBIOSIS - Abstract
Ascorbate (AsA) is the most abundant antioxidant in plant cells and a cofactor for a large number of key enzymes. However, the mechanism of how AsA levels are regulated in plant cells remains unknown. The Arabidopsis (Arabidopsis thaliana) activation-tagged mutant AT23040 showed a pleiotropic phenotype, including ozone resistance, rapid growth, and leaves containing higher AsA than wild-type plants. The phenotype was caused by activation of a purple acid phosphatase (PAP) gene, At PAP15, which contains a dinuclear metal center in the active site. AtPAP15 was universally expressed in all tested organs in wild-type plants. Overexpression of AtPAP15 with the 35S cauliflower mosaic virus promoter produced mutants with up to 2-fold increased foliar AsA, 20% to 30% decrease in foliar phytate, enhanced salt tolerance, and decreased abscisic acid sensitivity. Two independent SALK T-DNA insertion mutants in AtPAP15 had 30% less foliar AsA and 15% to 20% more phytate than wild-type plants and decreased tolerance to abiotic stresses. Enzyme activity of partially purified AtPAP15 from plant crude extract and recombinant AtPAP15 expressed in bacteria and yeast was highest when phytate was used as substrate, indicating that AtPAP15 is a phytase. Recombinant AtPAP15 also showed enzyme activity on the substrate myoinositol-1-phosphate, indicating that the AtPAP15 is a phytase that hydrolyzes myoinositol hexakisphosphate to yield myoinositol and free phosphate. Myoinositol is a known precursor for AsA biosynthesis in plants. Thus, AtPAP15 may modulate AsA levels by controlling the input of myoinositol into this branch of AsA biosynthesis in Arabidopsis. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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12. Multiple E3 ligases act as antiviral factors against SARS-CoV-2 via inducing the ubiquitination and degradation of ORF9b.
- Author
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Miao Yu, Jie Li, Wenying Gao, Zhaolong Li, and Wenyan Zhang
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UBIQUITIN ligases , *SARS-CoV-2 , *TYPE I interferons , *LIGASES , *VIRAL proteins , *UBIQUITINATION - Abstract
Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) open reading frame 9b (ORF9b) antagonizes the antiviral type I and III interferon (IFN) responses and is ubiquitinated and degraded via the ubiquitin-proteasome pathway. However, E3 ubiquitin ligases that mediate the polyubiquitination and degradation of ORF9b remain unknown. In this study, we identified 14 E3 ligases that specifically bind to SARS-CoV-2 ORF9b. Specifically, three E3 ligases, HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 (HUWE1), ubiquitin protein ligase E3 component n-recognin 4 (UBR4), and UBR5, induced K48-linked polyubiquitination and degradation of ORF9b, thereby attenuating ORF9b-mediated inhibition of the IFN response and SARS-CoV-2 replication. Moreover, each E3 ligase performed this function independent of the other two E3 ligases. Therefore, the three E3 ligases identified in this study as anti-SARS-CoV-2 host factors provide novel molecular insight into the virus-host interaction. IMPORTANCE Ubiquitination is an important post-translational modification that regulates multiple biological processes, including viral replication. Identification of E3 ubiquitin ligases that target viral proteins for degradation can provide novel targets for antagonizing viral infections. Here, we identified multiple E3 ligases, including HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 (HUWE1), ubiquitin protein ligase E3 component n-recognin 4 (UBR4), and UBR5, that ubiquitinated and induced the degradation of severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) open reading frame 9b (ORF9b), an interferon (IFN) antagonist, thereby enhancing IFN production and attenuating SARS-CoV-2 replication. Our study provides new possibilities for drug development targeting the interaction between E3 ligases and ORF9b. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. Neisseria meningitidis Serogroup W135 Sequence Type 11, Anhui Province, China, 2011-2013.
- Author
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Shoukui Hu, Wenyan Zhang, Furong Li, Zhongwang Hu, Erjian Ma, Tianli Zheng, Yingying Zhao, Wei Li, Haijian Zhou, Zhujun Shao, and Jianguo Xu
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NEISSERIA meningitidis , *BACTERIAL diseases , *TEENAGE boys , *VACCINATION , *DISEASES - Abstract
The article reports on 15 infections caused by Neisseria meningitidis serogroup W135 sequence type (ST) 11 from 2011 to 2013 in the Chinese town of Hefei in Anhui Province where there was a high risk for epidemic cerebrospinal meningitis. It details the fatal cases of serogroup W135 infection in two teenage boys who have not recently traveled and no history of vaccination with tetravalent polysaccharide vaccine. It also notes the other 13 cases which occurred in close contacts of the boys.
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- 2014
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14. Deubiquitinase USP1 regulates sarbecovirus ORF6 protein function.
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Wenying Gao, Liuli Wang, Wenzhe Cui, Hongfei Wang, Guofeng Huang, Zhaolong Li, Guangquan Li, and Wenyan Zhang
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VIRUS diseases , *TYPE I interferons , *PROTEINS , *INTERFERONS , *VIRAL replication , *DRUG target , *INFECTION prevention , *INTERFERON receptors - Abstract
SARS-CoV-2 belongs to the subgenus Sarbecovirus, which universally encodes the accessory protein ORF6. SARS-CoV-2 ORF6 is an antagonist of the interferon (IFN)-mediated antiviral response and plays an important role in viral infections. However, the mechanism by which the host counteracts the function of ORF6 to restrict viral replication remains unclear. In this study, we found that most ORF6 proteins encoded by sarbecoviruses could be ubiquitinated and subsequently degraded via the proteasome pathway. Through extensive screening, we identified that the deubiquitinase USP1, which effectively and broadly deubiquitinates sarbecovirus ORF6 proteins, stabilizes ORF6 proteins, resulting in enhanced viral replication. Therefore, ubiquitination and deubiquitination of ORF6 are important for antagonizing IFN-mediated antiviral signaling and influencing the virulence of SARS-CoV-2. These findings highlight an essential molecular mechanism and may provide a novel target for therapeutic interventions against viral infections. IMPORTANCE The ORF6 proteins encoded by sarbecoviruses are essential for effective viral replication and infection and are important targets for developing effective intervention strategies. In this study, we confirmed that sarbecovirus ORF6 proteins are important antagonists of the host immune response and identified the regulatory mechanisms of ubiquitination and deubiquitination of most sarbecovirus ORF6 proteins. Moreover, we revealed that DUB USP1 prevents the proteasomal degradation of all ORF6 proteins, thereby promoting the virulence of SARS-CoV-2. Thus, impeding ORF6 function is helpful for attenuating the virulence of sarbecoviruses. Therefore, our findings provide a deeper understanding of the molecular mechanisms underlying sarbecovirus infections and offer potential new therapeutic targets for the prevention and treatment of these infections. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Effects of Willing Powder Mediating Notch Pathway on Mice with Nephrotic Syndrome.
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Luotong JING, Yihan LI, Honglanxi LI, Wenyan ZHANG, Lin QIN, and Ning LIANG
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NEPHROTIC syndrome , *POWDERS , *MICE , *GENE expression , *WESTERN immunoblotting , *DOXORUBICIN , *KIDNEYS - Abstract
[Objectives] This study was conducted to investigate the renal protective effects of Wuling Powder on mice with nephrotic syndrome (NS) based on Notch pathway. [ Methods ] Sixty KM mice were randomly divided into normal group, model group, prednisone acetate positive group, high-dose Wuling Powder group, medium-dose Wuling Power group and low-dose Wuling Power group, with 10 mice in each group. Three days after prophylactic administration, a comprehensive nephropathy model was prepared by injecting 1 mg/ml doxorubicin hydrochloride solution (7.5 mg/kg) into the tail vein. After successful modeling, prednisone acetate and Wuling SAN were given high, medium and low doses for intervention for 28 d, respectively. After that, urinary protein and creatinine contents of mice in each group were detected, and pathological damage of renal tissue was observed by HE and Masson staining. The mRNA levels of Notchl, Jaggedl and Hesl in mouse kidney tissues were detected by RT-PCR, and the expression levels of Notchl, Jaggedl and Hesl proteins were detected by Western blot. [Results] Wuling Powder could effectively reduce the contents of urine protein (P <0. 01) and Scr (P <0. 01) in NS mice, and alleviate the pathological injury of kidney. Compared with the model group, the prednisone acetate group and various Wuling Powder groups could down-regulate the expressions of Notchl, Jaggedl and Hesl mRNA in the kidney tissue of mice (P<0. 01), and the expression of Notchl protein in the renal tissue of mice decreased (P<0.01). The contents of Hesl in the prednisone acetate group and the high- and medium-dose Wuling Powder groups significantly decreased (P <0. 05). [ Conclusions] Wuling Powder could protect the kidneys in mice with NS through Notch pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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16. Bottom sediment dynamics driven by deep sea contour currents and mesoscale eddies on the Jianfeng slope, northern South China Sea.
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Hui Chen, Wenyan Zhang, and Xinong Xie
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EDDIES , *MESOSCALE eddies , *SEDIMENTS , *SEAS - Published
- 2018
17. Identification of a Cullin5-ElonginB-ElonginC E3 Complex in Degradation of Feline Immunodeficiency Virus Vif-Mediated Feline APOBEC3 Proteins.
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Jiawen Wang, Wenyan Zhang, Mingyu Lv, Tao Zuo, Wei Kong, and Xianghui Yu
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FELINE immunodeficiency virus , *UBIQUITIN , *PROTEINS , *RETROVIRUS diseases , *VIRUSES - Abstract
Various feline APOBEC3 (fA3) proteins exhibit broad antiviral activities against a wide range of viruses, such as feline immunodeficiency virus (FIV), feline foamy virus (FFV), and feline leukemia virus (FeLV), as well as those of other species. This activity can be counteracted by the FIV Vif protein, but the mechanism by which FIV Vif suppresses fA3s is unknown. In the present study, we demonstrated that FIV Vif could act via a proteasome-dependent pathway to overcome fA3s. FIV Vif interacted with feline cellular proteins Cullin5 (Cul5), ElonginB, and ElonginC to form an E3 complex to induce degradation of fA3s. Both the dominant-negative Cul5 mutant and a C-terminal hydrophilic replacement ElonginC mutant potently disrupted the FIV Vif activity against fA3s. Furthermore, we identified a BC-box motif in FIV Vif that was essential for the recruitment of E3 ubiquitin ligase and also required for FIV Vifmediated degradation of fA3s. Moreover, despite the lack of either a Cul5-box or a HCCH zinc-binding motif, FIV Vif specifically selected Cul5. Therefore, FIV Vif may interact with Cul5 via a novel mechanism. These finding imply that SOCS proteins may possess distinct mechanisms to bind Cul5 during formation of the Elongin-Cullin-SOCS box complex. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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18. Chirality enhances oxygen reduction.
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Yutao Sang, Tassinari, Francesco, Santra, Kakali, Wenyan Zhang, Fontanesi, Claudio, Bloom, Brian P., Waldeck, David H., Fransson, Jonas, and Naaman, Ron
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OXYGEN reduction , *OXYGEN electrodes , *CHIRALITY , *SPIN-orbit interactions , *FUEL cells - Abstract
Controlled reduction of oxygen is important for developing clean energy technologies, such as fuel cells, and is vital to the existence of aerobic organisms. The process starts with oxygen in a triplet ground state and ends with products that are all in singlet states. Hence, spin constraints in the oxygen reduction must be considered. Here, we show that the electron transfer efficiency from chiral electrodes to oxygen (oxygen reduction reaction) is enhanced over that from achiral electrodes. We demonstrate lower overpotentials and higher current densities for chiral catalysts versus achiral ones. This finding holds even for electrodes composed of heavy metals with large spin–orbit coupling. The effect results from the spin selectivity conferred on the electron current by the chiral assemblies, the chiral-induced spin selectivity effect. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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19. Chemokine PF4 Inhibits EV71 and CA16 Infections at the Entry Stage.
- Author
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Zhichao Pei, Hong Wang, Zhilei Zhao, Xiang Chen, Chen Huan, and Wenyan Zhang
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CELL receptors , *HEPATITIS C virus , *CARRIER proteins , *DENGUE viruses , *PEPTIDES , *BLOOD platelet activation , *HEPATITIS C , *COXSACKIEVIRUSES - Abstract
Platelet factor 4 (PF4) or the CXC chemokine CXCL4 is the most abundant protein within the a-granules of platelets. Previous studies found that PF4 regulates infections of several viruses, including HIV-1, H1N1, hepatitis C virus (HCV), and dengue virus. Here, we show that PF4 is an inhibitor of enterovirus A71 (EV71) and coxsackievirus A16 (CA16) infections. The secreted form of PF4 from transfected cells or soluble purified PF4 from Escherichia coli, even lacking signal peptide affected secretion, obviously inhibited the propagation of EV71 and CA16. Mechanistically, we demonstrated that PF4 blocked the entry of the virus into the host cells by interactions with VP3 proteins of EV71/CA16 and the interaction with SCARB2 receptor-mediated EV71 and CA16 endocytosis. As expected, the incubation of anti-PF4 antibody with PF4 blocked PF4 inhibition on EV71 and CA16 infections further supported the above conclusion. Importantly, pretreatment of EV71 viruses with PF4 significantly protected the neonatal mice from EV71 lethal challenge and promoted the survival rate of infected mice. PF4 derived from natural platelets by EV71/CA16 activation also presented strong inhibition on EV71 and CA16. In summary, our study identified a new host factor against EV71 and CA16 infections, providing a novel strategy for EV71 and CA16 treatment. IMPORTANCE The virus's life cycle starts with binding to cell surface receptors, resulting in receptor-mediated endocytosis. Targeting the entry of the virus into target cells is an effective strategy to develop a novel drug. EV71 and CA16 are the major pathogens that cause hand, foot, and mouth disease (HFMD) outbreaks worldwide since 2008. However, the treatment of EV71 and CA16 infections is mainly symptomatic because there is no approved drug. Therefore, the underlying pathogenesis of EV71/CA16 and the interaction between host-EV71/CA16 need to be further investigated to develop an inhibitor. Here, we identified PF4 as a potent entry inhibitor of EV71 and CA16 via binding to VP3 proteins of EV71 and CA16 or binding to receptor SCARB2. In the EV71 infection model, PF4 protected mice from EV71 lethal challenge and promoted the survival rate of EV71-infected mice. Our study suggests that PF4 represents a potential candidate host factor for anti-EV71 and CA16 infections. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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20. A new method for lint percentage non-destructive detection based on optical penetration imaging.
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Lijie Geng, Zhikun Ji, Pengji Yan, Ruiliang Zhang, Zhifeng Zhang, Yusheng Zhai, Wenyan Zhang, and Kun Yang
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COTTONSEED , *OPTICAL images , *COMPUTER vision , *IMAGE processing , *PERCENTILES , *COTTON picking - Abstract
Lint percentage of seed cotton is one of the important bases for pricing in the trading segment. Unfortunately, the conventional methods of lint percentage are manually operated, which relies on the abundant experience of experts, and restrained by personal, physical and environmental factors. Up to date, the calculation of the lint percentage of seed cotton has not fully automated. In this paper, we proposed a non-destructive detection method for automatically obtaining lint percentage of seed cotton based on optical penetration imaging and machine vision, for the first time to our knowledge. The cotton seed image was obtained by the penetration imaging setup with a LED white backlight source. To accurately identify the number of cotton seeds, the image features of the cotton seed was studied and three key features was been found, which are the circumference, area, and greyscale value, respectively. A calculation system based on the three key features was presented to process the images and then automatically calculate the lint percentage of seed cotton. The first step of the system is to segment the original image using adaptive thresholding followed by morphological operations. Afterwards, the number of cotton seed was obtained by the three key features of the cotton seed. Then, the lint percentage was achieved by a professional industry formula. The suggested lint percentage detection methods were verified by the experiments with two seed cotton varieties samples of H219 and ZHM19. The experimental results indicated that the detection average accuracy of the developed system for seed cotton varieties H219 and ZHM19 were 96.33% and 95.40%. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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21. Optimization and Characterization of Candidate Strain for Coxsackievirus A16 Inactivated Vaccine.
- Author
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Guanchen Liu, Junliang Chang, Wenyan Zhang, Xiao-Fang Yu, Jingliang Li, Xin Liu, and Jiaxin Yang
- Subjects
- *
HAND, foot & mouth disease , *ENTEROVIRUSES , *INACTIVATED oil adjuvant vaccines , *EPIDEMICS , *MULTIDIMENSIONAL chromatography - Abstract
Coxsackievirus A16 (CA16) and enterovirus 71 (EV71), both of which can cause hand, foot and mouth disease (HFMD), are responsible for large epidemics in Asian and Pacific areas. Although inactivated EV71 vaccines have completed testing in phase III clinical trials in Mainland China, CA16 vaccines are still under development. A Vero cell-based inactivated CA16 vaccine was developed by our group. Screening identified a CA16 vaccine strain (CC024) isolated from HFMD patients, which had broad cross-protective abilities and satisfied all requirements for vaccine production. Identification of the biological characteristics showed that the CA16CC024 strain had the highest titer (107.5 CCID50/mL) in Vero cells, which would benefit the development of an EV71/CA16 divalent vaccine. A potential vaccine manufacturing process was established, including the selection of optimal time for virus harvesting, membrane for diafiltration and concentration, gel-filtration chromatography for the down-stream virus purification and virus inactivation method. Altogether, the analyses suggested that the CC-16, a limiting dilution clone of the CC024 strain, with good genetic stability, high titer and broad-spectrum immunogenicity, would be the best candidate strain for a CA16 inactivated vaccine. Therefore, our study provides valuable information for the development of a Vero cell-based CA16 or EV71-CA16 divalent inactivated vaccine. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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22. Inhibitory Effects of Citral, Cinnamaldehyde, and Tea Polyphenols on Mixed Biofilm Formation by Foodborne Staphylococcus aureus and Salmonella Enteritidis.
- Author
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HONGMEI ZHANG, WENYUAN ZHOU, WENYAN ZHANG, ANLIN YANG, YANLAN LIU, YAN JIANG, SHAOSONG HUANG, and JIANYU SU
- Subjects
- *
FOOD microbiology , *STAPHYLOCOCCUS aureus , *SALMONELLA enteritidis , *CITRAL , *POLYPHENOLS - Abstract
Biofilms are significant hazards in the food industry. In this study, we investigated the effects of food additive such as citral, cinnamaldehyde, and tea polyphenols on mixed biofilm formation by foodborne Staphylococcus aureus and Salmonella serotype Enteritidis. The adhesion rates of mixed strains in sub-MIC of additives were determined by a microtiter plate assay and bacterial communication signal autoinducer 2 (AI-2) production via a bioluminescence reporter Vibrio harveyi BB170. The structure of mixed biofilm was analyzed using scanning electron microscopy. The effect of the disinfectants hydrogen peroxide, sodium hypochlorite, and peracetic acid was tested on the mixed biofilm. Our results demonstrated that citral, cinnamaldehyde, and tea polyphenols were able to significantly inhibit mixed biofilm formation, while citral could reduce the synthesis of AI-2. Conversely, we observed a significant increase in AI-2 mediated by cinnamaldehyde. Tea polyphenols at lower concentrations induced AI-2 synthesis; however, AI-2 synthesis was significantly inhibited at higher concentrations (300 m g/ml). Food additives inhibited the adhesion of mixed bacteria on stainless steel chips and increased the sensitivity of the mixed biofilm to disinfectants. In conclusion, citral, cinnamaldehyde, and tea polyphenols had strong inhibitory effects on mixed biofilm formation and also enhanced the effect of disinfectant on mixed biofilm formation. This study provides a scientific basis for the application of natural food additives to control biofilm formation of foodborne bacteria. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
23. Clinicopathological and Prognostic Characteristics of Hepatoid Adenocarcinoma of the Stomach.
- Author
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Jinlin Yang, Rui Wang, Wenyan Zhang, Wen Zhuang, Mojin Wang, and Chengwei Tang
- Subjects
- *
ADENOCARCINOMA , *GASTRIC emptying , *CARCINOMA , *IMMUNOSTAINING , *MEDICAL care - Abstract
The present study was undertaken to clarify the association of the clinicopathological features of hepatoid adenocarcinoma (HAC) in the stomach, a special kind of carcinoma that histologically resembled hepatocellular carcinoma (HCC) and is characterized by large amounts of a-fetoprotein (AFP) in serum, with the clinical prognosis. We collected the data of the clinicopathological features and the follow-up information from a total of 31 HACs from January 2005 to December 2012 in our hospital. High lymphatic (54.8%) and distant (25.8%) metastasis rates before surgery, large proportion of advanced HACs (71.0%) at admission, short median overall survival time (6 months), and low three-year survival rate (22.6%) suggested that HAC in the stomach was an aggressive disease, resulting in a poor prognosis. And pTNM stages, immunohistochemical staining of AFP, CEA, CK7, and CK20 had statistically relation with the survival as the independent risk factors, P < 0.05. Therefore, early and clear differentiation of HAC from cancerous or noncancerous conditions with AFP elevation and assessment of high risk patients by histopathology may improve the clinical prognosis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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24. Host Restriction Factor A3G Inhibits the Replication of Enterovirus D68 by Competitively Binding the 59 Untranslated Region with PCBP1.
- Author
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Zhaolong Li, Xu Yang, Zhilei Zhao, Xin Liu, and Wenyan Zhang
- Subjects
- *
DNA viruses , *RNA viruses , *COXSACKIEVIRUSES , *ENTEROVIRUSES , *RETROVIRUSES , *NUCLEOTIDES , *VIRAL nonstructural proteins - Abstract
The host restriction factor APOBEC3G (A3G) inhibits an extensive variety of viruses, including retroviruses, DNA viruses, and RNA viruses. Our study shows that A3G inhibits enterovirus 71 (EV71) and coxsackievirus A16 (CA16) via competitively binding the 59 untranslated region (UTR) with the host protein poly(C)-binding protein 1 (PCBP1), which is required for the replication of multiple EVs. However, whether A3G inhibits other EVs in addition to EV71 and CA16 has not been investigated. Here, we demonstrate that A3G could inhibit the replication of EVD68, which requires PCBP1 for its replication, but not CA6, which does not require PCBP1 for replication. Further investigation revealed that the nucleic-acid-binding activity of A3G is required for EVD68 restriction, similar to the mechanism presented for EV71 restriction. Mechanistically, A3G competitively binds to the cloverleaf (1 to 123 nucleotides [nt]) and the stem-loop IV (234 to 446 nt) domains of the EVD68 59 UTR with PCBP1, thereby inhibiting the 59 UTR activity of EVD68; by contrast, A3G does not interact with CA6 59 UTR, resulting in no effect on CA6 replication. Moreover, the nonstructural protein 2C, encoded by EVD68, overcomes A3G suppression by inducing A3G degradation via the autophagylysosome pathway. Our findings revealed that A3G might have broad-spectrum antiviral activity against multiple EVs through this general mechanism, and they might provide important information for the development of an anti-EV strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
25. SAMHD1 Inhibits Multiple Enteroviruses by Interfering with the Interaction between VP1 and VP2 Proteins.
- Author
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Zhilei Zhao, Zhaolong Li, Chen Huan, Xin Liu, and Wenyan Zhang
- Subjects
- *
ENTEROVIRUSES , *IMMUNOREGULATION , *BINDING sites , *NATURAL immunity - Abstract
Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) possesses multiple biological activities such as virus restriction, innate immunity regulation, and autoimmunity. Our previous study demonstrated that SAMHD1 potently inhibits the replication of enterovirus 71 (EV71). In this study, we observed that SAMHD1 also restricts multiple enteroviruses (EVs), including coxsackievirus A16 (CA16) and enterovirus D68 (EVD68), but not coxsackievirus A6 (CA6). Mechanistically, SAMHD1 competitively interacted with the same domain in VP1 that binds to VP2 of EV71 and EVD68, thereby interfering with the interaction between VP1 and VP2, and therefore viral assembly. Moreover, we showed that the SAMHD1 T592A mutant maintained the EV71 inhibitory effect by attenuating the interaction between VP1 and VP2, whereas the T592D mutant failed to. We also demonstrated that SAMHD1 could not inhibit CA6 because a different binding site is required for the SAMHD1 and VP1 interaction. Our findings reveal the mechanism of SAMHD1 inhibition of multiple EVs, and this could potentially be important for developing drugs against a broad range of EVs. IMPORTANCE Enterovirus causes a wide variety of diseases, such as hand, foot, and mouth disease (HFMD), which is a severe public problem threatening children under 5 years. Therefore, identifying essential genes which restrict EV infection and exploring the underlying mechanisms are necessary to develop an effective strategy to inhibit EV infection. In this study, we report that host restrictive factor SAMHD1 has broad-spectrum antiviral activity against EV71, CA16, and EVD68 independent of its well-known deoxynucleoside triphosphate triphosphohydrolase (dNTPase) or RNase activity. Mechanistically, SAMHD1 restricts EVs by competitively interacting with the same domain in VP1 that binds to VP2 of EVs, thereby interfering with the interaction between VP1 and VP2, and therefore viral assembly. In contrast, we also demonstrated that SAMHD1 could not inhibit CA6 because a different binding site is required for the SAMHD1 and CA6 VP1 interaction. Our study reveals a novel mechanism for the SAMHD1 anti-EV replication activity. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
26. Deubiquitinating Enzyme USP21 Inhibits HIV-1 Replication by Downregulating Tat Expression.
- Author
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Wenying Gao, Guangquan Li, Simin Zhao, Hong Wang, Chen Huan, Baisong Zheng, Chunlai Jiang, and Wenyan Zhang
- Subjects
- *
HIV , *UBIQUITINATION , *ANTI-HIV agents , *VIRUS diseases , *PROTEOLYSIS , *ENZYMES , *DEUBIQUITINATING enzymes - Abstract
Ubiquitination plays an important role in human immunodeficiency virus 1 (HIV-1) infection. HIV proteins such as Vif and Vpx mediate the degradation of the host proteins APOBEC3 and SAMHD1, respectively, through the proteasome pathway. However, whether deubiquitylating enzymes play an essential role in HIV-1 infection is largely unknown. Here, we demonstrate that the deubiquitinase USP21 potently inhibits HIV-1 production by indirectly downregulating the expression of HIV-1 transactivator of transcription (Tat), which is essential for transcriptional elongation in HIV-1. USP21 deubiquitylates Tat via its deubiquitinase activity, but a stronger ability to reduce Tat expression than a dominant-negative ubiquitin mutant (Ub-KO) showed that other mechanisms may contribute to USP21-mediated inhibition of Tat. Further investigation showed that USP21 downregulates cyclin T1 mRNA levels by increasing methylation of histone K9 in the promoter of cyclin T1, a subunit of the positive transcription elongation factor b (P-TEFb) that interacts with Tat and transactivation response element (TAR) and is required for transcription stimulation and Tat stability. Moreover, USP21 had no effect on the function of other HIV-1 accessory proteins, including Vif, Vpr, Vpx, and Vpu, indicating that USP21 was specific to Tat. These findings improve our understanding of USP21-mediated functional suppression of HIV-1 production. IMPORTANCE Ubiquitination plays an essential role in viral infection. Deubiquitinating enzymes (DUBs) reverse ubiquitination by cleaving ubiquitins from target proteins, thereby affecting viral infection. The role of the members of the USP family, which comprises the largest subfamily of DUBs, is largely unknown in HIV-1 infection. Here, we screened a series of USP members and found that USP21 inhibits HIV-1 production by specifically targeting Tat but not the other HIV-1 accessory proteins. Further investigations revealed that USP21 reduces Tat expression in two ways. First, USP21 deubiquitinates polyubiquitinated Tat, causing Tat instability, and second, USP21 reduces the mRNA levels of cyclin T1 (CycT1), an important component of P-TEFb, that leads to Tat downregulation. Thus, in this study, we report a novel role of the deubiquitinase, USP21, in HIV-1 infection. USP21 represents a potentially useful target for the development of novel anti-HIV drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. Spatial patterns and conservation of genetic and phylogenetic diversity of wildlife in China.
- Author
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Yibo Hu, Huizhong Fan, Youhua Chen, Jiang Chang, Xiangjiang Zhan, Hua Wu, Baowei Zhang, Meng Wang, Wenyan Zhang, Lin Yang, Xian Hou, Xing Shen, Tao Pan, Wei Wu, Jun Li, Haihua Hu, and Fuwen Wei
- Subjects
- *
BIOLOGICAL evolution , *PARSIMONIOUS models , *BIRD populations , *NUMBERS of species , *SPECIES diversity , *WILDLIFE conservation , *BIOTIC communities , *SPATIAL variation - Abstract
The article offers information on the spatial patterns and conservation of genetic and phylogenetic diversity of wildlife in China. It mentions about the genetic diversity and phylogenetic diversity reflect the evolutionary potential and history of species. It discusses that findings helps guide national-level genetic diversity conservation plans and a post-2020 biodiversity conservation framework.
- Published
- 2021
- Full Text
- View/download PDF
28. GBP5 is an interferon-induced inhibitor of respiratory syncytial virus.
- Author
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Zhaolong Li, Xinglong Qu, Xin Liu, Chen Huan, Hong Wang, Zhilei Zhao, Xu Yang, Shucheng Hua, and Wenyan Zhang
- Subjects
- *
RESPIRATORY syncytial virus , *UBIQUITINATION , *GUANOSINE triphosphatase , *UBIQUITIN ligases , *CARRIER proteins , *NLRP3 protein , *G proteins , *PATHOLOGY - Abstract
Guanylate binding protein 5 (GBP5) belongs to the guanosine triphosphatase (GTPase) subfamily, which is mainly induced by interferon γ (IFN-γ) and is involved in many important cellular processes, including inflammasome activation and innate immunity against a wide variety of microbial pathogens. However, it is unknown whether GBP5 inhibits respiratory syncytial virus (RSV) infection. Here, we identified GBP5 as an effector of the anti-RSV activity of IFN-γ and found that in children, the weaker immune response, especially the weaker IFN-γ response and the decreased GBP5 expression, leads to RSV susceptibility. Furthermore, we revealed that GBP5 reduced the cell-associated levels of the RSV small hydrophobic (SH) protein, which was identified as a viroporin. In contrast, overexpression of the SH protein rescued RSV replication in the presence of GBP5. The GBP5-induced decrease in intracellular SH protein levels is because GBP5 promotes the release of the SH protein into the cell culture. Moreover, the GBP5 C583A mutants at the C-terminus or lacking the C-terminus region, which impair GBP5 localisation in the Golgi, could not inhibit RSV infection, whereas the GTPase-defective GBP5 maintained RSV inhibition, suggesting that Golgi localisation but not the GTPase activity of GBP5 is required for RSV inhibition. Interestingly, we found that RSV infection or RSV G protein downregulates GBP5 expression by upregulating DZIP3, an E3 ligase, which induces GBP5 degradation through the K48-ubiquitination and proteasomal pathways. Thus, this study reveals a complicated interplay between host restrictive factor GBP5 and RSV infection and provides important information for understanding the pathogenesis of the RSV. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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29. NF-ĸB-Interacting Long Noncoding RNA Regulates HIV-1 Replication and Latency by Repressing NF-ĸB Signaling.
- Author
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Hong Wang, Yue Liu, Chen Huan, Jing Yang, Zhaolong Li, Baisong Zheng, Yingchao Wang, and Wenyan Zhang
- Subjects
- *
LINCRNA , *HIV , *VIRAL tropism , *HISTONE acetylation , *T cells , *BINDING sites - Abstract
NF-ĸB-interacting long noncoding RNA (NKILA) was recently identified as a negative regulator of NF-ĸB signaling and plays an important role in the development of various cancers. It is well known that NF-ĸB-mediated activation of human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR)-driven gene expression is required for HIV-1 transcription and reactivation of latency. However, whether NKILA plays essential roles in HIV-1 replication and latency is unclear. Here, by ectopic expression and silencing experiments, we demonstrate that NKILA potently inhibits HIV-1 replication in an NF-ĸB-dependent manner by suppressing HIV-1 LTR promoter activity. Moreover, NKILA showed broad-spectrum inhibition on the replication of HIV-1 clones with different coreceptor tropisms as well as on LTR activity of various HIV-1 clinical subtypes. Chromatin immunoprecipitation (ChIP) assays revealed that NKILA expression abolishes the recruitment of p65 to the duplicated ĸB binding sites in the HIV-1 LTR. NKILA mutants disrupting NF-ĸB inhibition also lost the ability to inhibit HIV-1 replication. Notably, HIV-1 infection or reactivation significantly downregulated NKILA expression in T cells in order to facilitate viral replication. Downregulated NKILA was mainly due to reduced acetylation of histone K27 on the promoter of NKILA by HIV-1 infection, which blocks NKILA expression. Knockdown of NKILA promoted the reactivation of latent HIV-1 upon phorbol myristate acetate (PMA) stimulation, while ectopic NKILA suppressed the reactivation in a wellestablished clinical model of withdrawal of azidothymidine (AZT) in vitro. These findings improve our understanding of the functional suppression of HIV-1 replication and latency by NKILA through NF-ĸB signaling. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
30. The pyrimidine analog FNC potently inhibits the replication of multiple enteroviruses.
- Author
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Na Xu, Jing Yang, Baisong Zheng, Yan Zhang, Yiming Cao, Chen Huan, Shengqi Wang, Junbiao Chang, and Wenyan Zhang
- Subjects
- *
COXSACKIEVIRUSES , *ENTEROVIRUSES , *FOOT & mouth disease , *RNA replicase , *ISOTHERMAL titration calorimetry , *NEONATAL infections , *RNA synthesis , *LINEZOLID - Abstract
Human enteroviruses (EVs), including coxsackieviruses, the numbered enteroviruses and echoviruses, cause a wide range of diseases, such as hand, foot and mouth disease HFMD), encephalitis, myocarditis, acute flaccid myelitis (AFM), pneumonia, and bronchiolitis. Therefore, broad-spectrum anti-EV drugs are urgently needed to treat EV infection. Here, we demonstrate that FNC, a small nucleoside analog inhibitor that has been demonstrated to be a potent inhibitor of HIV and entered into a clinical phase II trial in China, potently inhibits the viral replication of a multitude of EVs, including enterovirus 71 (EV71), coxsackievirus A16 (CA16), CA6, EVD68, and CVB3, at the nanomolar level. The antiviral mechanism of FNC involves mainly positive- and negative-strand RNA synthesis inhibition by targeting and competitively inhibiting the activity of EV71 viral RNA-dependent RNA polymerase (3Dpol), as demonstrated through RT-qPCR, in vitro 3Dpol activity and isothermal titration calorimetry (ITC) experiments. We further demonstrated that FNC treatment every two days with 1 mg/kg in EV71 and CA16 infection neonatal mouse models successfully protected mice from lethal challenge with EV71 and CA16 viruses and reduced the viral load in various tissues. These findings provide important information for the clinical development of FNC as a broad-spectrum inhibitor of human EV pathogens. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
31. Long Noncoding RNA uc002yug.2 Activates HIV-1 Latency through Regulation of mRNA Levels of Various RUNX1 Isoforms and Increased Tat Expression.
- Author
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Chen Huan, Zhaolong Li, Shanshan Ning, Hong Wang, Xiao-Fang Yu, and Wenyan Zhang
- Subjects
- *
HIV , *AIDS , *CARCINOGENESIS , *RNA , *VIRAL replication - Abstract
The HIV-1 reservoir is a major obstacle to complete eradication of the virus. Although many proteins and RNAs have been characterized as regulators in HIV-1/AIDS pathogenesis and latency, only a few long noncoding RNAs (lncRNAs) have been shown to be closely associated with HIV-1 replication and latency. In this study, we demonstrated that lncRNA uc002yug.2 plays a key role in HIV-1 replication and latency. uc002yug.2 potentially enhances HIV-1 replication, long terminal repeat (LTR) activity and the activation of latent HIV-1 in both cell lines and CD4+ T cells from patients. Further investigation revealed that uc002yug.2 activates latent HIV-1 through downregulating RUNX1b and -1c and upregulating Tat protein expression. The accumulated evidence supports our model that the Tat protein has the key role in the uc002yug.2-mediated regulatory effect on HIV-1 reactivation. Moreover, uc002yug.2 showed an ability to activate HIV-1 similar to that of suberoylanilide hydroxamic acid or phorbol 12-myristate 13-acetate using latently infected cell models. These findings improve our understanding of lncRNA regulation of HIV-1 replication and latency, providing new insights into potential targeted therapeutic interventions. IMPORTANCE The latent viral reservoir is the primary obstacle to curing HIV-1 disease. To date, only a few lncRNAs, which play major roles in various biological processes, including viral infection, have been identified as regulators in HIV-1 latency. In this study, we demonstrated that lncRNA uc002yug.2 is important for both HIV-1 replication and activation of latent viruses. Moreover, uc002yug.2 was shown to activate latent HIV-1 through regulating alternative splicing of RUNX1 and increasing the expression of Tat protein. These findings highlight the potential merit of targeting lncRNA uc002yug.2 as an activating agent for latent HIV-1. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
32. Disruption of MDA5-Mediated Innate Immune Responses by the 3C Proteins of Coxsackievirus A16, Coxsackievirus A6, and Enterovirus D68.
- Author
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Yajuan Rui, Jiaming Su, Hong Wang, Junliang Chang, Shaohua Wang, Wenwen Zheng, Yong Cai, Wei Wei, James T. Gordy, Richard Markham, Wei Kong, Wenyan Zhang, and Xiao-Fang Yu
- Subjects
- *
COXSACKIEVIRUSES , *ENTEROVIRUSES , *IMMUNE response , *HAND, foot & mouth disease , *COXSACKIEVIRUS diseases - Abstract
Coxsackievirus A16 (CV-A16), CV-A6, and enterovirus D68 (EV-D68) belong to the Picornaviridae family and are major causes of hand, foot, and mouth disease (HFMD) and pediatric respiratory disease worldwide. The biological characteristics of these viruses, especially their interplay with the host innate immune system, have not been well investigated. In this study, we discovered that the 3Cpro proteins from CV-A16, CV-A6, and EV-D68 bind melanoma differentiation-associated gene 5 (MDA5) and inhibit its interaction with MAVS. Consequently, MDA5-triggered type I interferon (IFN) signaling in the retinoic acid-inducible gene I-like receptor (RLR) pathway was blocked by the CV-A16, CV-A6, and EV-D68 3Cpro proteins. Furthermore, the CV-A16, CV-A6, and EV-D68 3Cpro proteins all cleave transforming growth factor βactivated kinase 1 (TAK1), resulting in the inhibition of NF-κB activation, a host response also critical for Toll-like receptor (TLR)-mediated signaling. Thus, our data demonstrate that circulating HFMD-associated CV-A16 and CV-A6, as well as severe respiratory disease-associated EV-D68, have developed novel mechanisms to subvert host innate immune responses by targeting key factors in the RLR and TLR pathways. Blocking the ability of 3Cpro proteins from diverse enteroviruses and coxsackieviruses to interfere with type I IFN induction should restore IFN antiviral function, offering a potential novel antiviral strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
33. Inhibition of Vpx-Mediated SAMHD1 and Vpr-Mediated Host Helicase Transcription Factor Degradation by Selective Disruption of Viral CRL4 (DCAF1) E3 Ubiquitin Ligase Assembly.
- Author
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Hong Wang, Haoran Guo, Jiaming Su, Yajuan Rui, Wenwen Zheng, Wenying Gao, Wenyan Zhang, Zhaolong Li, Guanchen Liu, Markham, Richard B., Wei Wei, and Xiao-Fang Yua
- Subjects
- *
HELICASES , *TRANSCRIPTION factors , *UBIQUITIN ligases , *LENTIVIRUSES , *VIRAL proteins , *HOST-virus relationships - Abstract
The lentiviral accessory proteins Vpx and Vpr are known to utilize CRL4 (DCAF1) E3 ligase to induce the degradation of the host restriction factor SAMHD1 or host helicase transcription factor (HLTF), respectively. Selective disruption of viral CRL4 (DCAF1) E3 ligase could be a promising antiviral strategy. Recently, we have determined that posttranslational modification (neddylation) of Cullin-4 is required for the activation of Vpx-CRL4 (DCAF1) E3 ligase. However, the mechanism of Vpx/Vpr-CRL4 (DCAF1) E3 ligase assembly is still poorly understood. Here, we report that zinc coordination is an important regulator of Vpx-CRL4 E3 ligase assembly. Residues in a conserved zinc-binding motif of Vpx were essential for the recruitment of the CRL4 (DCAF1) E3 complex and Vpx-induced SAMHD1 degradation. Importantly, altering the intracellular zinc concentration by treatment with the zinc chelator N,N,N=-tetrakis-(2=-pyridylmethyl)ethylenediamine (TPEN) potently blocked Vpx-mediated SAMHD1 degradation and inhibited wild-type SIVmac (simian immunodeficiency virus of macaques) infection of myeloid cells, even in the presence of Vpx. TPEN selectively inhibited Vpx and DCAF1 binding but not the Vpx-SAMHD1 interaction or Vpx virion packaging. Moreover, we have shown that zinc coordination is also important for the assembly of the HIV-1 Vpr-CRL4 E3 ligase. In particular, Vpr zinc-binding motif mutation or TPEN treatment efficiently inhibited Vpr-CRL4 (DCAF1) E3 ligase assembly and Vpr-mediated HLTF degradation or Vpr-induced G2 cell cycle arrest. Collectively, our study sheds light on a conserved strategy by the viral proteins Vpx and Vpr to recruit host CRL4 (DCAF1) E3 ligase, which represents a target for novel antihuman immunodeficiency virus (HIV) drug development. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
34. FLUORIDE INDUCES APOPTOSIS IN MC3T3-E1 OSTEOBLASTS BY ALTERING ROS LEVELS AND MITOCHONDRIAL MEMBRANE POTENTIALS.
- Author
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Xiaoyan Yan, Xiaolin Tian, Lu Wang, Wenli Zhou, Wenyan Zhang, Yi Lv, Yulan Qiu, and Tong Wang
- Subjects
- *
PHYSIOLOGICAL effects of fluorides , *MITOCHONDRIAL membranes , *OSTEOBLASTS - Abstract
This research investigated the relationship between the levels of reactive oxygen species (ROS), mitochondrial membrane potentials, and apoptosis in MC3T3-E1 osteoblasts (OB) by administering varying concentrations of the fluoride ion. Sodium fluoride (NaF), at concentrations of 0, 1, 5, 10, and 30 mg/L, was administered to cultured OB. Hematoxylin and eosin (HE) and 4',6-diamidino-2-phenylindole (DAPI) staining were used to observe the effects of fluoride on OB apoptosis. In addition, the ROS levels and the mitochondrial membrane potentials of the OB were analyzed with a Fluorescence Activated Cell Sorter (FACS) using labeling probes DCFH-DA and JC-1 after fluoride treatment for 72 hr. There were pronounced negative effects on OB survival from long-term NaF treatment. These negative effects included apoptosis, increased ROS levels, and decreased mitochondrial membrane potentials. Our results demonstrated that fluoride-induced OB apoptosis is mediated by the direct effects of fluoride on ROS levels and mitochondrial membrane potentials. [ABSTRACT FROM AUTHOR]
- Published
- 2017
35. Mutation of Glycosylation Sites in BST-2 Leads to Its Accumulation at Intracellular CD63-Positive Vesicles without Affecting Its Antiviral Activity against Multivesicular Body-Targeted HIV-1 and Hepatitis B Virus.
- Author
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Zhu Han, Mingyu Lv, Ying Shi, Jinghua Yu, Junqi Niu, Xiao-Fang Yu, and Wenyan Zhang
- Subjects
- *
GLYCOSYLATION , *GENETIC mutation , *CD antigens , *ANTIVIRAL agents , *HIV - Abstract
BST-2/tetherin blocks the release of various enveloped viruses including HIV-1 with a "physical tethering" model. The detailed contribution of N-linked glycosylation to this model is controversial. Here, we confirmed that mutation of glycosylation sites exerted an effect of post-translational mis-trafficking, leading to an accumulation of BST-2 at intracellular CD63-positive vesicles. BST-2 with this phenotype potently inhibited the release of multivesicular body-targeted HIV-1 and hepatitis B virus, without affecting the co-localization of BST-2 with EEA1 and LAMP1. These results suggest that N-linked glycosylation of human BST-2 is dispensable for intracellular virion retention and imply that this recently discovered intracellular tethering function may be evolutionarily distinguished from the canonical antiviral function of BST-2 by tethering nascent virions at the cell surface. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
36. Broad protection with an inactivated vaccine against primary-isolated lethal enterovirus 71 infection in newborn mice.
- Author
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Junliang Chang, Jingliang Li, Xin Liu, Guanchen Liu, Jiaxin Yang, Wei Wei, Wenyan Zhang, and Xiao-Fang Yu
- Subjects
- *
ENTEROVIRUS diseases , *ORAL diseases , *HAND diseases , *FOOT diseases , *SEROTYPES , *LABORATORY mice , *ANIMAL models in research , *VACCINATION - Abstract
Background: Circulating enterovirus 71 (EV-A71)-associated hand, foot, and mouth disease is on the rise in the Asian-Pacific region. Although animal models have been developed using mouse-adapted EV-A71 strains, mouse models using primary EV-A71 isolates are scarce. Lethal animal models with circulating EV-A71 infection would contribute to studies of pathogenesis as well as vaccine development and evaluation. Results: In this study, we established a lethal mouse model using primary EV-A71 isolates from patients infected with serotypes that are currently circulating in humans. We also characterized the dose-dependent virulence and pathologic changes of circulating EV-A71 in this mouse model. Most importantly, we have established this mouse model as a suitable system for EV-A71 vaccine evaluation. An inactivated EV-A71 vaccine candidate offered complete protection from death induced by various circulating EV-A71 viruses to neonatal mice that were born to immunized female mice. The sera of the immunized dams and their pups showed higher neutralization titers against multiple circulating EV-A71 viruses. Conclusions: Thus, our newly established animal model using primary EV-A71 isolates is helpful for future studies on viral pathogenesis and vaccine and drug development. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. Broad protection with an inactivated vaccine against primary-isolated lethal enterovirus 71 infection in newborn mice.
- Author
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Junliang Chang, Jingliang Li, Xin Liu, Guanchen Liu, Jiaxin Yang, Wei Wei, Wenyan Zhang, and Xiao-Fang Yu
- Abstract
Background: Circulating enterovirus 71 (EV-A71)-associated hand, foot, and mouth disease is on the rise in the Asian-Pacific region. Although animal models have been developed using mouse-adapted EV-A71 strains, mouse models using primary EV-A71 isolates are scarce. Lethal animal models with circulating EV-A71 infection would contribute to studies of pathogenesis as well as vaccine development and evaluation. Results: In this study, we established a lethal mouse model using primary EV-A71 isolates from patients infected with serotypes that are currently circulating in humans. We also characterized the dose-dependent virulence and pathologic changes of circulating EV-A71 in this mouse model. Most importantly, we have established this mouse model as a suitable system for EV-A71 vaccine evaluation. An inactivated EV-A71 vaccine candidate offered complete protection from death induced by various circulating EV-A71 viruses to neonatal mice that were born to immunized female mice. The sera of the immunized dams and their pups showed higher neutralization titers against multiple circulating EV-A71 viruses. Conclusions: Thus, our newly established animal model using primary EV-A71 isolates is helpful for future studies on viral pathogenesis and vaccine and drug development. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
38. Experimental Demonstration of Longitudinal Beam Phase-Space Linearizer in a Free-Electron Laser Facility by Corrugated Structures.
- Author
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Haixiao Deng, Meng Zhang, Chao Feng, Tong Zhang, Xingtao Wang, Taihe Lan, Lie Feng, Wenyan Zhang, Xiaoqing Liu, Haifeng Yao, Lei Shen, Bin Li, Junqiang Zhang, Xuan Li, Wencheng Fang, Dan Wang, Couprie, Marie-emmanuelle, Guoqiang Lin, Bo Liu, and Qiang Gu
- Subjects
- *
ELECTRON beam research , *FREE electron lasers , *PHASE space , *BANDWIDTHS , *POLARIZATION (Electricity) , *LINEAR energy transfer - Abstract
Removal of the undesired time-energy correlations in the electron beam is of paramount importance for efficient lasing of a high-gain free-electron laser. Recently, it has been theoretically and experimentally demonstrated that the longitudinal wakefield excited by the electrons themselves in a corrugated structure allows for precise control of the electron beam phase space. In this Letter, we report the first utilization of a corrugated structure as a beam linearizer in the operation of a seeded free-electron laser driven by a 140 MeV linear accelerator, where a gain of ~10000 over spontaneous emission was achieved at the second harmonic of the 1047 nm seed laser, and a free-electron laser bandwidth narrowing by 50% was observed, in good agreement with the theoretical expectations. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
39. Requirement of HIV-1 Vif C-terminus for Vif-CBF-β interaction and assembly of CUL5-containing E3 ligase.
- Author
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Hong Wang, Guoyue Lv, Xiaohong Zhou, Zhaolong Li, Xin Liu, Xiao-Fang Yu, and Wenyan Zhang
- Abstract
Background: Human immunodeficiency virus type 1 (HIV-1) Vif hijacks an E3 ligase to suppress natural APOBEC3 restriction factors, and core binding factor â (CBF-â) is required for this process. Although an extensive region of Vif spanning most of its N-terminus is known to be critical for binding with CBF-â, involvement of the Vif C-terminus in the interaction with CBF-â has not been fully investigated. Results: Here, through immunoprecipitation analysis of Vif C-terminal truncated mutants of various lengths, we identified that CBF-â binding requires not only certain amino acids (G126A, E134A, Y135A and G138A) in the HCCH region but also the HCCH motif itself, which also affects the Vif-mediated suppression of APOBEC3G/APOBEC3F (A3G/A3F). These mutants still maintained interactions with substrate A3G or A3F as well as other cellular factors ElonginB/C (ELOB/C), indicating that their structures were not functionally affected. Moreover, by determining that the BC box also is necessary for CBF-â interaction in vivo, we speculate that binding to ELOB/C induces conformational changes in Vif, facilitating its interaction with CBF-â and consequent interaction with CUL5. Conclusions: These results provide important information on the assembly of the Vif-CUL5-E3 ubiquitin ligase. Identification of the new binding interface with CBF-â at the C-terminus of HIV-1 Vif also provides novel targets for the development of HIV-1 inhibitors. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
40. Core Binding Factor Beta Plays a Critical Role by Facilitating the Assembly of the Vif-Cullin 5 E3 Ubiquitin Ligase.
- Author
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Fribourgh, Jennifer L., Nguyen, Henry C., Wolfe, Leslie S., DeWitt, David C., Wenyan Zhang, Xiao-Fang Yu, Rhoades, Elizabeth, and Yong Xiong
- Subjects
- *
UBIQUITIN ligases , *VIRION , *CYTIDINE deaminase , *PROTEASOMES , *N-terminal residues , *ZINC-finger proteins - Abstract
The HIV-1 virion infectivity factor (Vif) targets the cellular cytidine deaminases APOBEC3G (A3G) and APOBEC3F (A3F) for degradation via the host ubiquitin-proteasome pathway. Vif recruits a cellular E3 ubiquitin ligase to polyubiquitinate A3G/F. The activity of Vif critically depends on the cellular core binding factor beta (CBFβ). In this study, we investigated the Vif-CBFβ interaction and the role of CBFβ in the E3 ligase assembly. Vif-CBFβ interaction requires an extensive region of Vif spanning most of its amino terminus and zinc finger region, and cullin 5 (Cul5) binding enhances the stability of the Vif-CBFβ interaction. Our results further demonstrate that CBFβ plays a critical role in facilitating Cul5 binding to the Vif/elongin B/elongin C complex. Vif, with or without bound substrate, is unable to bind Cul5 in the absence of CBFβ. These studies support the notion that CBFβ serves as a molecular chaperone to facilitate Vif-E3 ligase assembly. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
41. Evolutionarily Conserved Requirement for Core Binding Factor Beta in the Assembly of the Human Immunodeficiency Virus/Simian Immunodeficiency Virus Vif-Cullin 5-RING E3 Ubiquitin Ligase.
- Author
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Xue Han, Weizi Liang, Deping Hua, Xiaohong Zhou, Juan Du, Evans, Sean L., Qimeng Gao, Hong Wang, Viqueira, Rachel, Wei Wei, Wenyan Zhang, and Xiao-Fang Yu
- Subjects
- *
HIV , *SIMIAN immunodeficiency virus diseases , *VIRION , *UBIQUITIN ligases , *ELONGINS - Abstract
The human immunodeficiency virus type 1 (HIV-1)-encoded virion infectivity factor (Vif) is required to inactivate the host restriction factor APOBEC3 by engaging Cullin 5 (Cul5)-RING ubiquitin ligase (CRL5). Core binding factor beta (CBF-β) is a novel regulator of Vif-CRL5 function; as yet, its mechanism of regulation remains unclear. In the present study, we demonstrate that CBF-β promotion of Vif-CRL5 assembly is independent of its influence on Vif stability and is also a conserved feature of primate lentiviral Vif proteins. Furthermore, CBF-β is critical for the formation of the Vif-ElonginB/ElonginC-Cul5 core E3 ubiquitin ligase complex in vitro. CBF-β from diverse vertebrate species supported HIV-1 Vif function, indicating the conserved nature of Vif-CBF-β interfaces. Considering the importance of the interaction between Vif and CBF-β in viral CRL5 function, disrupting this interaction represents an attractive pharmacological intervention against HIV-1. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
42. Evolutionarily Conserved Requirement for Core Binding Factor Beta in the Assembly of the Human Immunodeficiency Virus/Simian Immunodeficiency Virus Vif-Cullin 5-RING E3 Ubiquitin Ligase.
- Author
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Xue Han, Weizi Liang, Deping Hua, Xiaohong Zhou, Juan Du, Evans, Sean L., Qimeng Gao, Hong Wang, Viqueira, Rachel, Wei Wei, Wenyan Zhang, and Xiao-Fang Yua
- Subjects
- *
HIV , *SIMIAN immunodeficiency virus , *UBIQUITIN ligases , *PROTEIN binding , *PROTEIN stability - Abstract
The human immunodeficiency virus type 1 (HIV-1)-encoded virion infectivity factor (Vif) is required to inactivate the host restriction factor APOBEC3 by engaging Cullin 5 (Cul5)-RING ubiquitin ligase (CRL5). Core binding factor beta (CBF-β) is a novel regulator of Vif-CRL5 function; as yet, its mechanism of regulation remains unclear. In the present study, we demonstrate that CBF-β promotion of Vif-CRL5 assembly is independent of its influence on Vif stability and is also a conserved feature of primate lentiviral Vif proteins. Furthermore, CBF-β is critical for the formation of the Vif-ElonginB/ElonginC-Cul5 core E3 ubiquitin ligase complex in vitro. CBF-β from diverse vertebrate species supported HIV-1 Vif function, indicating the conserved nature of Vif-CBF-β interfaces. Considering the importance of the interaction between Vif and CBF-β in viral CRL5 function, disrupting this interaction represents an attractive pharmacological intervention against HIV-1. IMPORTANCE HIV-1 encodes virion infectivity factor (Vif) to inactivate its host's antiviral APOBEC3 proteins. Vif triggers APOBEC3 degradation by forming Vif-Cullin 5 (Cul5)-RING ubiquitin ligase (CRL5). Core binding factor beta (CBF-β) is a novel regulator of Vif- CRL5 function whose mechanism of regulation remains poorly defined. In the present study, we demonstrate that the promotion of Vif-CRL5 assembly by CBF-β can be separated from its influence on Vif stability. The promotion of Vif-CRL5 assembly, but not the influence on Vif stability, is conserved among primate lentiviral Vif proteins: we found that CBF-β from diverse vertebrate species supported HIV-1 Vif function. Considering the importance of the interaction between Vif and CBF-β in viral CRL5 function and HIV-1 replication, disrupting this interaction is an attractive strategy against HIV-1. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
43. Core Binding Factor Beta Plays a Critical Role by Facilitating the Assembly of the Vif-Cullin 5 E3 Ubiquitin Ligase.
- Author
-
Fribourgh, Jennifer L., Nguyen, Henry C., Wolfe, Leslie S., DeWitt, David C., Wenyan Zhang, Xiao-Fang Yu, Rhoades, Elizabeth, and Yong Xiong
- Subjects
- *
VIRION , *UBIQUITIN ligases , *PROTEASOME inhibitors , *ANTIVIRAL agents , *N-terminal residues , *ZINC-finger proteins - Abstract
The HIV-1 virion infectivity factor (Vif) targets the cellular cytidine deaminases APOBEC3G (A3G) and APOBEC3F (A3F) for degradation via the host ubiquitin-proteasome pathway. Vif recruits a cellular E3 ubiquitin ligase to polyubiquitinate A3G/F. The activity of Vif critically depends on the cellular core binding factor beta (CBFβ). In this study, we investigated the Vif-CBFβ interaction and the role of CBFβ in the E3 ligase assembly. Vif-CBFβ interaction requires an extensive region of Vif spanning most of its amino terminus and zinc finger region, and cullin 5 (Cul5) binding enhances the stability of the Vif-CBFβ interaction. Our results further demonstrate that CBFβ plays a critical role in facilitating Cul5 binding to the Vif/elongin B/elongin C complex. Vif, with or without bound substrate, is unable to bind Cul5 in the absence of CBFβ. These studies support the notion that CBFβ serves as a molecular chaperone to facilitate Vif-E3 ligase assembly. IMPORTANCE The host antiviral restriction factors A3G/F inhibit viral replication. The HIV-1 protein Vif targets A3G/F for degradation. This immune evasion activity of Vif is dependent on the cellular factor CBFβ. Multiple regions of Vif are known to be important for Vif function, but the mechanisms are unclear. The studies described here provide important information about the Vif-CBFβ interaction interface and the function of CBFβ in E3 ligase assembly. In particular, our comprehensive Vif-CBFβ interface mapping results help to delineate the role of various Vif regions, determining if they are important for binding CBFβ or A3G/F. Furthermore, our studies reveal an important potential mechanism of CBFβ that has not been shown before. Our results suggest that CBFβ may serve as a molecular chaperone to enable Vif to adopt an appropriate conformation for interaction with the Cul5-based E3 ligase. This study advances our understanding of how CBFβ facilitates the Vif-mediated degradation of APOBEC3 proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
44. Dopamine-ModifiedAlginate Beads Reinforced by Cross-Linkingvia Titanium Coordination or Self-Polymerization and Its Applicationin Enzyme Immobilization.
- Author
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Xiaoli Wang, Zhongyi Jiang, Jiafu Shi, Chunhong Zhang, Wenyan Zhang, and Hong Wu
- Subjects
- *
DOPAMINE , *ALGINIC acid , *TITANIUM compounds , *COORDINATE covalent bond , *POLYMERIZATION , *CALCIUM ions , *HYDROGEN-ion concentration - Abstract
Twonovel kinds of dopamine-modified alginate beads were developedby using titanium(IV) coordination or self-polymerization, besidesthe conventional Ca2+ion cross-linking. Alginate was modifiedwith dopamine (AlgDA) via EDC/NHS chemistry. Fourier transforminfrared spectroscopy (FTIR) and circular dichroism (CD) characterizationconfirmed that dopamine was covalently attached preferentially tothe mannuronic acid residues of alginate; thus, gel-forming abilityof the as-prepared AlgDAwas well retained. The titanium(IV)coordination-reinforced alginate beads [Ca–Ti(AlgDA)] were prepared by cross-linking with Ti4+and Ca2+. Covalently cross-linking-reinforced alginate beads (Ca–AlgPDA) were also prepared by self-polymerization of dopamineand cross-linking with Ca2+. The swelling of Ca–AlgPDAand Ca–Ti(AlgDA) were both obviouslyinhibited, and the mechanical properties were enhanced by 3 timescompared to those of Ca–Alg beads. The as-prepared beads wereutilized for immobilization of alcohol dehydrogenase (YADH). The immobilizationefficiency of Ca–Ti(AlgDA) and Ca–AlgPDAreached up to 100% and 89%, respectively, both notablyhigher than that of Ca–Alg (67.4%). Stabilities of the immobilizedYADH in Ca–AlgPDAand Ca–Ti(AlgDA) toward pH, storage, and recycling were all improved compared withthose immobilized in Ca–Alg. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
45. Differential Requirements for HIV-1 Vif-Mediated APOBEC3G Degradation and RUNX1-Mediated Transcription by Core Binding Factor Beta.
- Author
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Juan Du, Ke Zhao, Yajuan Rui, Peng Li, Xiaohong Zhou, Wenyan Zhang, and Xiao-Fang Yu
- Subjects
- *
HIV , *AMINO acids , *GENETIC transcription , *ORGANIC acids , *BINDING sites - Abstract
Core binding factor beta (CBFß), a transcription regulator through RUNX binding, was recently reported critical for Vif function. Here, we mapped the primary functional domain important for Vif function to amino acids 15 to 126 of CBFß. We also revealed that different lengths and regions are required for CBFß to assist Vif or RUNX. The important interaction domains that are uniquely required for Vif but not RUNX function represent novel targets for the development of HIV inhibitors. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
46. Characterization of Full-Length Enterovirus 71 Strains from Severe and Mild Disease Patients in Northeastern China.
- Author
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Xiaomei Wang, Chunfeng Zhu, Wanguo Bao, Ke Zhao, Junqi Niu, Xiao-Fang Yu, and Wenyan Zhang
- Subjects
- *
MICROORGANISMS , *CYTOSKELETAL proteins , *RECOMBINANT viruses , *RECOMBINANT microorganisms , *LOWER ionosphere , *GENETIC recombination - Abstract
Human enterovirus 71 (EV71)-associated hand, foot, and mouth disease (HFMD) has been a leading cause of childhood infection in China since 2008. Epidemic and molecular characteristics of HFMD have been examined in many areas of China, including the central and southern regions. However, clinical and genetic characterization of EV71 in the northeastern region of China is scarce. In this study, a series of analyses were performed on seven full-length EV71 sequences from HFMD patients who had either severe or mild disease. We have determined that these seven circulating EV71 viruses from Changchun, China are actually complex recombinant viruses involving multiple type A human enterovirus (HEV). Classified as EV71 subtype C4 (EV71 C4), these Changchun EV71 viruses contain genetic recombination events between the CA4, CA5, EV71B4 and EV71C1 strains. Most of the structural protein region (P1) of these viruses resembled that of the prototype EV71 C1 strains. The non-structural protein domains (P2 and P3) showed a high degree of similarity with CA4, CA5 and EV71 B4 in different regions. The 59UTR had unclassified recombination,while partial 3D region of these viruses showed a high degree of similarity to CA16. Phylogenetic analysis of full-length or partial sequences of isolates from severe or mild disease patients in Changchun always formed a single cluster in various phylogenetic analyses of different genomic regions, suggesting that all seven strains originated from one single common ancestor. There was no correlation between viral genomic sequence and virulence. Thus, we found that circulating recombinant forms of EV71 are prevalent among HFMD patients in Northeastern China. The existence of a unique cluster of EV71 related viruses in Northeast China has important implications for vaccine development that would address the increasing prevalence of HFMD. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
47. 7SL RNA Mediates Virion Packaging of the Antiviral Cytidine Deaminase APOBEC3G.
- Author
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Tao Wang, Chunjuan Tian, Wenyan Zhang, Kun Luo, Sarkis, Phuong Thi Nguyen, Lillian Yu, Bindong Liu, Yunkai Yu, and Xiao-Fang Yu
- Subjects
- *
RNA , *ADENOSINE deaminase , *ANTIVIRAL agents , *RETROVIRUS diseases , *RNA polymerases , *MESSENGER RNA , *TRANSFER RNA , *PREVENTION - Abstract
Cytidine deaminase APOBEC3G (A3G) has broad antiviral activity against diverse retroviruses and/or retrotransposons, and its antiviral functions are believed to rely on its encapsidation into virions in an RNA-dependent fashion. However, the cofactors of A3G virion packaging have not yet been identified. We demonstrate here that A3G selectively interacts with certain polymerase III (Pol III)-derived RNAs, including Y3 and 7SL RNAs. Among A3G-binding Pol III-derived RNAs, 7SL RNA was preferentially packaged into human immunodeficiency virus type 1 (HIV-1) particles. Efficient packaging of 7SL RNA, as well as A3G, was mediated by the RNA-binding nucleocapsid domain of HIV-1 Gag. A3G mutants that had reduced 7SL RNA binding but maintained wild-type levels of mRNA and tRNA binding were packaged poorly and had impaired antiviral activity. Reducing 7SL RNA packaging by overexpression of SRP19 proteins inhibited 7SL RNA and A3G virion packaging and impaired its antiviral function. Thus, 7SL RNA that is encapsidated into diverse retroviruses is a key cofactor of the antiviral A3G. This selective interaction of A3G with certain Pol III-derived RNAs raises the question of whether A3G and its cofactors may have as-yet-unidentified cellular functions. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
48. Overexpression of Tfam protects mitochondria against β-amyloid-induced oxidative damage in SH-SY5Y cells.
- Author
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Shangcheng Xu, Min Zhong, Lei Zhang, Yuan Wang, Zhou Zhou, Yutong Hao, Wenyan Zhang, Xuesen Yang, Aimin Wei, Liping Pei, and Zhengping Yu
- Subjects
- *
MITOCHONDRIAL DNA , *AMYLOID beta-protein , *TRANSCRIPTION factors , *OXIDATIVE stress , *MITOCHONDRIAL pathology , *GENE expression , *CELL-mediated cytotoxicity , *APOPTOSIS - Abstract
There is strong evidence that β-amyloid (Aβ) causes oxidative stress and induces mitochondrial dysfunction in the pathogenesis of Alzheimer’s disease. Mitochondrial transcription factor A (Tfam) has multiple roles in the maintenance of mtDNA. To study the protective roles of Tfam against amyloid neurotoxicity, we established SH-SY5Y cell lines stably overexpressing Tfam and exposed them to 10 μm Aβ1-42 for 24 h. We found that Tfam overexpression attenuated Aβ1-42-induced cell viability damage and apoptosis. In addition, Tfam overexpression significantly suppressed the increase in excess reactive oxygen species and reversed the reduction in cytochrome c oxidase activity and ATP production induced by Aβ1-42. Furthermore, overexpression of ΔC-Tfam, which has no functional domain for stimulating mtDNA transcription but can still maintain the mtDNA nucleoid formation and mtDNA copy number, also exhibited protective effects against Aβ1-42 cytotoxicity in SH-SY5Y cells. Together, our data suggest that Tfam overexpression protects mitochondria against Aβ-induced oxidative damage in SH-SY5Y cells. These beneficial effects may be attributable to the roles of Tfam in maintaining mtDNA nucleoid formation and mtDNA copy number. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
49. CD4+/CD56+ hematodermic neoplasm: a report of three cases.
- Author
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Hong Ji, Lin Wang, Dan Li, Wenyan Zhang, Chuan Wan, Chen Xu, and Gandi Li
- Subjects
- *
CASE studies , *NODULAR disease , *SKIN disease diagnosis , *DISEASE complications , *PERIODIC health examinations , *TUMOR growth , *RADIOTHERAPY - Abstract
The article presents several case studies on the complications of the nodules. The patients went through either physical examination, clinical examination and ultasonography in order to diagnose the disease. The patients were diagnosed to have CD4+/CD5+ hematodermic neoplasm wherein chemotherapy and radiotherapy were used for treatment. The treatment showed various results depending on the condition of the disease.
- Published
- 2009
- Full Text
- View/download PDF
50. Adenovirus E4orf6 assembles with Cullin5-ElonginB-ElonginC E3 ubiquitin ligase through an HIV/SIV Vif-like BC-box to regulate p53.
- Author
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Kun Luo, Ehrlich, Elana, Zuoxiang Xiao, Wenyan Zhang, Ketner, Gary, and Xiao-Fang Yu
- Subjects
- *
VIRAL proteins , *ADENOVIRUSES , *GENETIC regulation , *P53 antioncogene , *UBIQUITIN , *LIGASES , *GENE silencing - Abstract
The adenovirus protein E4orf6 targets p53 for polyubiquitination and proteasomal degradation and is known to form a complex with the Cul5-ElonginB-ElonginC E3 ubiquitin ligase. However, whether Cul5 is directly responsible for the E4orf6-mediated degradation of p53 remains unclear. By using a dominant-negative mutant of CUl5 and silencing Cul5 expression through RNA interference, we have now demonstrated that E4orf6-mediated p53 degradation requires CUl5. Furthermore, we have identified a lenti-viral Vif-like BC-box motif in E4orf6 that is highly conserved among adenoviruses from multiple species. More importantly, we have shown that this Vif-like BC-box is essential for the recruitment of Cul5-ElonginB-ElonginC E3 ubiquitin ligase by E4orf6 and is also required for E4orf6-mediated p53 degradation. E4orf6 selectively recruited Cul5 despite the lack of either a Cul5-box, which is used by cellular substrate receptors to recruit Cul5, or a newly identified HCCH zinc-binding motif, which is used by primate lentiviral Vif to recruit Cul5. Therefore, adenovirus E4orf6 molecules represent a novel family of viral BC-box proteins the cellular ancestor of which is as yet unknown. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
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