31 results on '"Yinan Kan"'
Search Results
2. Correction: Corrigendum: Engineering and optimising deaminase fusions for genome editing
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Luhan Yang, Adrian W. Briggs, Wei Leong Chew, Prashant Mali, Marc Guell, John Aach, Daniel Bryan Goodman, David Cox, Yinan Kan, Emal Lesha, Venkataramanan Soundararajan, Feng Zhang, and George Church
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Science - Abstract
Nature Communications 7: Article number: 13330 (2016); Published 2 November 2016; Updated 9 October 2017. The original version of this Article contained an error in the email address of the corresponding author George Church. The correct email is gchurch@genetics.med.harvard.edu. The error has been corrected in the HTML and PDF versions of the Article.
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- 2017
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3. The mechanism of gene targeting in human somatic cells.
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Yinan Kan, Brian Ruis, Sherry Lin, and Eric A Hendrickson
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Genetics ,QH426-470 - Abstract
Gene targeting in human somatic cells is of importance because it can be used to either delineate the loss-of-function phenotype of a gene or correct a mutated gene back to wild-type. Both of these outcomes require a form of DNA double-strand break (DSB) repair known as homologous recombination (HR). The mechanism of HR leading to gene targeting, however, is not well understood in human cells. Here, we demonstrate that a two-end, ends-out HR intermediate is valid for human gene targeting. Furthermore, the resolution step of this intermediate occurs via the classic DSB repair model of HR while synthesis-dependent strand annealing and Holliday Junction dissolution are, at best, minor pathways. Moreover, and in contrast to other systems, the positions of Holliday Junction resolution are evenly distributed along the homology arms of the targeting vector. Most unexpectedly, we demonstrate that when a meganuclease is used to introduce a chromosomal DSB to augment gene targeting, the mechanism of gene targeting is inverted to an ends-in process. Finally, we demonstrate that the anti-recombination activity of mismatch repair is a significant impediment to gene targeting. These observations significantly advance our understanding of HR and gene targeting in human cells.
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- 2014
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4. The HSV-1 exonuclease, UL12, stimulates recombination by a single strand annealing mechanism.
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April J Schumacher, Kareem N Mohni, Yinan Kan, Eric A Hendrickson, Jeremy M Stark, and Sandra K Weller
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Production of concatemeric DNA is an essential step during HSV infection, as the packaging machinery must recognize longer-than-unit-length concatemers; however, the mechanism by which they are formed is poorly understood. Although it has been proposed that the viral genome circularizes and rolling circle replication leads to the formation of concatemers, several lines of evidence suggest that HSV DNA replication involves recombination-dependent replication reminiscent of bacteriophages λ and T4. Similar to λ, HSV-1 encodes a 5'-to-3' exonuclease (UL12) and a single strand annealing protein [SSAP (ICP8)] that interact with each other and can perform strand exchange in vitro. By analogy with λ phage, HSV may utilize viral and/or cellular recombination proteins during DNA replication. At least four double strand break repair pathways are present in eukaryotic cells, and HSV-1 is known to manipulate several components of these pathways. Chromosomally integrated reporter assays were used to measure the repair of double strand breaks in HSV-infected cells. Single strand annealing (SSA) was increased in HSV-infected cells, while homologous recombination (HR), non-homologous end joining (NHEJ) and alternative non-homologous end joining (A-NHEJ) were decreased. The increase in SSA was abolished when cells were infected with a viral mutant lacking UL12. Moreover, expression of UL12 alone caused an increase in SSA, which was completely eliminated when a UL12 mutant lacking exonuclease activity was expressed. UL12-mediated stimulation of SSA was decreased in cells lacking the cellular SSAP, Rad52, and could be restored by coexpressing the viral SSAP, ICP8, indicating that an SSAP is also required. These results demonstrate that UL12 can specifically stimulate SSA and that either ICP8 or Rad52 can function as an SSAP. We suggest that SSA is the homology-mediated repair pathway utilized during HSV infection.
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- 2012
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5. Genetic modifications designed for xenotransplantation attenuate sialoadhesin-dependent binding of human erythrocytes to porcine macrophages
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Kaitlyn Petitpas, Zahra Habibabady, Veronica Ritchie, Margaret R. Connolly, Lars Burdorf, Wenning Qin, Yinan Kan, Jacob V. Layer, Juliet N. Crabtree, Michele E. Youd, William F. Westlin, Diogo M. Magnani, Richard N. Pierson, and Agnes M. Azimzadeh
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Transplantation ,Immunology - Abstract
The phenomenon of diminishing hematocrit after in vivo liver and lung xenotransplantation and during ex vivo liver xenoperfusion has largely been attributed to action by resident liver porcine macrophages, which bind and destroy human erythrocytes. Porcine sialoadhesin (siglec-1) was implicated previously in this interaction. This study examines the effect of porcine genetic modifications, including knockout of the CMAH gene responsible for expression of Neu5Gc sialic acid, on the adhesion of human red blood cells (RBCs) to porcine macrophages. Wild-type (WT) porcine macrophages and macrophages from several strains of genetically engineered pigs, including CMAH gene knockout and several human transgenes (TKO+hTg), were incubated with human RBCs and "rosettes" (≥3 erythrocytes bound to one macrophage) were quantified by microscopy. Our results show that TKO+hTg genetic modifications significantly reduced rosette formation. The monoclonal antibody 1F1, which blocks porcine sialoadhesin, significantly reduced rosette formation by WT and TKO+hTg macrophages compared with an isotype control antibody. Further, desialation of human RBCs with neuraminidase before addition to WT or TKO+hTg macrophages resulted in near-complete abrogation of rosette formation, to a level not significantly different from porcine RBC rosette formation on porcine macrophages. These observations are consistent with rosette formation being mediated by binding of sialic acid on human RBCs to sialoadhesin on porcine macrophages. In conclusion, the data predict that TKO+hTg genetic modifications, coupled with targeting of porcine sialoadhesin by the 1F1 mAb, will attenuate erythrocyte sequestration and anemia during ex vivo xenoperfusion and following in vivo liver, lung, and potentially other organ xenotransplantation.
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- 2022
6. Extensive germline genome engineering in pigs
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Violette Paragas, Jacob V. Layer, Marc Güell, William F. Westlin, Luhan Yang, Juan Xiong, Weilin Wang, Shengyi Mao, Yinan Kan, Ranjith P. Anand, Deling Jiao, Zhongquan Sun, Mengyuan Xu, George M. Church, Lydia Lamriben, Xiaobin Song, Yu Luo, Lei Le, Hong-Ye Zhao, Hong-Jiang Wei, Michele Youd, Mailin Li, Yangbin Gao, Qi Zhang, Hongwei Dou, Dharmendra Goswami, Haydy George, Meng Yang, Yanan Yue, Yixuan Zhou, Zhuo Li, Shi Yun Wang, Lingling Song, James F. Markmann, Yuan Ding, Wenning Qin, Xueqiong Wang, Jiajia Wu, Tien Dat Nguyen, Xin Fang, Jianxiong Guo, and Weihong Xu
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0301 basic medicine ,Xenotransplantation ,medicine.medical_treatment ,Transgene ,Sus scrofa ,Transplantation, Heterologous ,Biomedical Engineering ,Medicine (miscellaneous) ,Endogenous retrovirus ,Bioengineering ,Biology ,Germline ,Mixed Function Oxygenases ,Genome engineering ,Gene Knockout Techniques ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,CRISPR-Associated Protein 9 ,medicine ,Animals ,Cells, Cultured ,Genetics ,Galactosyltransferases ,Computer Science Applications ,Transplantation ,Germ Cells ,030104 developmental biology ,N-Acetylgalactosaminyltransferases ,CRISPR-Cas Systems ,Genetic Engineering ,030217 neurology & neurosurgery ,Biotechnology - Abstract
The clinical applicability of porcine xenotransplantation-a long-investigated alternative to the scarce availability of human organs for patients with organ failure-is limited by molecular incompatibilities between the immune systems of pigs and humans as well as by the risk of transmitting porcine endogenous retroviruses (PERVs). We recently showed the production of pigs with genomically inactivated PERVs. Here, using a combination of CRISPR-Cas9 and transposon technologies, we show that pigs with all PERVs inactivated can also be genetically engineered to eliminate three xenoantigens and to express nine human transgenes that enhance the pigs' immunological compatibility and blood-coagulation compatibility with humans. The engineered pigs exhibit normal physiology, fertility and germline transmission of the 13 genes and 42 alleles edited. Using in vitro assays, we show that cells from the engineered pigs are resistant to human humoral rejection, cell-mediated damage and pathogenesis associated with dysregulated coagulation. The extensive genome engineering of pigs for greater compatibility with the human immune system may eventually enable safe and effective porcine xenotransplantation.
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- 2020
7. 414.1: Long-term (>1 Year) Rejection/TMA Free Survival of Kidney Xenografts With Triple Xenoantigen Knockout and Multiple Human Transgenes in Nonhuman Primates
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Grace Lassiter, Takayuki Hirose, David Ma, Ashley D’Attilio, Ivy Rosales, Rudy Matheson, Daniel Cloonan, Robert B. Colvin, Wenning Qin, Yinan Kan, Jacob Layer, Ranjith Anand, Violette Paragas, Luis Queroz, Xiaoqing Tan, Ian Kohnle, Katherine Stiede, Katherine Hall, Michele Youd, Michael Curtis, James F. Markmann, and Tatsuo Kawai
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Transplantation - Published
- 2022
8. Kidney transplantation from triple-knockout pigs expressing multiple human proteins in cynomolgus macaques
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Luhan Yang, Kathryn Stiede, James F. Markmann, Rudy Matheson, Luis M Queiroz, Jacob V. Layer, Michael Curtis, Yinan Kan, Ivy A. Rosales, David W.L. Ma, Katherine C Hall, Taylor M. Coe, Michele Youd, Charles G. Rickert, Robert B. Colvin, Hajime Sasaki, Wenning Qin, Takayuki Hirose, William F. Westlin, Violette Paragas, Tatsuo Kawai, and Grace Lassiter
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Graft Rejection ,Swine ,Transgene ,Xenotransplantation ,medicine.medical_treatment ,Transplantation, Heterologous ,Andrology ,Animals, Genetically Modified ,medicine ,Immunology and Allergy ,Animals ,Humans ,Pharmacology (medical) ,Human proteins ,Kidney transplantation ,Transplantation ,Kidney ,biology ,business.industry ,Antibody titer ,T-cell depletion ,medicine.disease ,Kidney Transplantation ,Macaca fascicularis ,medicine.anatomical_structure ,biology.protein ,Antibody ,business - Abstract
Porcine cells devoid of three major carbohydrate xenoantigens, αGal, Neu5GC, and SDa (TKO) exhibit markedly reduced binding of human natural antibodies. Therefore, it is anticipated that TKO pigs will be better donors for human xenotransplantation. However, previous studies on TKO pigs using old world monkeys (OWMs) have been disappointing because of higher anti-TKO pig antibodies in OWMs than humans. Here, we show that long-term survival of renal xenografts from TKO pigs that express additional human transgenes (hTGs) can be achieved in cynomolgus monkeys. Kidney xenografts from TKO-hTG pigs were transplanted into eight cynomolgus recipients without pre-screening for low anti-pig antibody titers. Two recipients of TKO-hTG xenografts with low expression of human complement regulatory proteins (CRPs) (TKO-A) survived for 2 and 61 days, whereas six recipients of TKO-hTG xenografts with high CRP expression (TKO-B) survived for 15, 20, 71, 135, 265, and 316 days. Prolonged CD4+ T cell depletion and low anti-pig antibody titers, which were previously reported important for long-term survival of αGal knock-out (GTKO) xenografts, were not always required for long-term survival of TKO-hTG renal xenografts. This study indicates that OWMs such as cynomolgus monkeys can be used as a relevant model for clinical application of xenotransplantation using TKO pigs.
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- 2021
9. Extensive Mammalian Germline Genome Engineering
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Ranjith P. Anand, Yu Luo, Shi Yun Wang, Hong-Jiang Wei, Juan Xiong, Deling Jiao, Violette Paragas, Yinan Kan, Yangbin Gao, Wenning Qin, Tien Dat Nguyen, George M. Church, Hongwei Dou, Jianxiong Guo, Yixuan Zhou, Shengyi Mao, Weihong Xu, Marc Güell, Jacob V. Layer, Hong-Ye Zhao, Mailin Li, Xin Fang, Xiaobin Song, Qi Zhang, Lei Le, William F. Westlin, Luhan Yang, Zhuo Li, Lingling Song, Xueqiong Wang, Jiajia Wu, Yuan Ding, James F. Markmann, Lydia Lamriben, Michele Youd, Weilin Wang, Zhongquan Sun, Mengyuan Xu, Meng Yang, Dharmendra Goswami, Yanan Yue, and Haydy George
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Transplantation ,Genetics ,Transgene ,Xenotransplantation ,medicine.medical_treatment ,medicine ,Endogenous retrovirus ,CRISPR ,Biology ,Genome ,Germline ,Genome engineering - Abstract
Xenotransplantation, specifically the use of porcine organs for human transplantation, has long been sought after as an alternative for patients suffering from organ failure. However, clinical application of this approach has been impeded by two main hurdles: 1) risk of transmission of porcine endogenous retroviruses (PERVs) and 2) molecular incompatibilities between donor pigs and humans which culminate in rejection of the graft. We previously demonstrated that all 25 copies of the PERV elements in the pig genome could be inactivated and live pigs successfully generated. In this study, we improved the scale of porcine germline editing from targeting a single repetitive locus with CRISPR to engineering 13 different genes using multiple genome engineering methods. we engineered the pig genome at 42 alleles using CRISPR-Cas9 and transposon and produced PERVKO·3KO·9TG pigs which carry PERV inactivation, xeno-antigen KO and 9 effective human transgenes. The engineered pigs exhibit normal physiology, fertility, and germline transmission of the edited alleles.In vitroassays demonstrated that these pigs gain significant resistance to human humoral and cell mediated damage, and coagulation dysregulations, similar to that of allotransplantation. Successful creation of PERVKO·3KO·9TG pigs represents a significant step forward towards safe and effective porcine xenotransplantation, which also represents a synthetic biology accomplishment of engineering novel functions in a living organism.One Sentence SummaryExtensive genome engineering is applied to modify pigs for safe and immune compatible organs for human transplantation
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- 2019
10. Human somatic cells deficient for RAD52 are impaired for viral integration and compromised for most aspects of homology-directed repair
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Yinan Kan, Nizar N. Batada, and Eric A. Hendrickson
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0301 basic medicine ,Genome instability ,DNA Repair ,Somatic cell ,genetic processes ,RAD52 ,Biology ,Biochemistry ,Genome ,Article ,Genomic Instability ,law.invention ,Homology directed repair ,Gene Knockout Techniques ,03 medical and health sciences ,chemistry.chemical_compound ,law ,Neoplasms ,Humans ,DNA Breaks, Double-Stranded ,Molecular Biology ,Gene ,fungi ,DNA ,Cell Biology ,Molecular biology ,Rad52 DNA Repair and Recombination Protein ,Cell biology ,Gene Expression Regulation, Neoplastic ,enzymes and coenzymes (carbohydrates) ,030104 developmental biology ,chemistry ,Recombinant DNA - Abstract
Homology-directed repair (HDR) maintains genomic integrity by eliminating lesions such as DNA double-strand breaks (DSBs), interstrand crosslinks (ICLs) and stalled replication forks and thus a deficiency in HDR is associated with genomic instability and cancer predisposition. The mechanism of HDR is best understood and most rigorously characterized in yeast. The inactivation of the fungal radiation sensitive 52 (RAD52) gene, which has both recombination mediator and single-strand annealing (SSA) activities in vitro, leads to severe HDR defects in vivo. Confusingly, however, the inactivation of murine and chicken RAD52 genes resulted in mouse and chicken cells, respectively, that were largely aphenotypic. To clarify this issue, we have generated RAD52 knockout human cell lines. Human RAD52-null cells retain a significant level of SSA activity demonstrating perforce that additional SSA-like activities must exist in human cells. Moreover, we confirmed that the SSA activity associated with RAD52 is involved in, but not absolutely required for, most HDR subpathways. Specifically, a deficiency in RAD52 impaired the repair of DNA DSBs and intriguingly decreased the random integration of recombinant adeno-associated virus (rAAV). Finally, an analysis of pan-cancer genome data from The Cancer Genome Atlas (TCGA) revealed an association between aberrant levels of RAD52 expression and poor overall survival in multiple cancers. In toto, our work demonstrates that RAD52 contributes to the maintenance of genome stability and tumor suppression in human cells.
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- 2017
11. SURVIVAL BENEFIT OF PIG-TO-BABOON LIVER XENOTRANSPLANTATION UTILIZING GENETICALLY MODIFIED SWINE
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James F. Markmann, Wenning Qin, Yinan Kan, Taylor M. Coe, Jacob V. Layer, Luhan Yang, Nikolaos Serifis, Shoko Kimura, Rudy Matheson, Danielle Detelich, Heidi Yeh, William F. Westlin, Michele Youd, Charles G. Rickert, and Ivy A. Rosales
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Transplantation ,Survival benefit ,Xenotransplantation ,medicine.medical_treatment ,biology.animal ,medicine ,Biology ,Virology ,Genetically modified organism ,Baboon - Published
- 2020
12. Conversion Tract Analysis of Homology-Directed Genome Editing Using Oligonucleotide Donors
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Yinan, Kan and Eric A, Hendrickson
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Gene Editing ,Luminescent Proteins ,Genes, Reporter ,Genetic Vectors ,Lentivirus ,Primary Cell Culture ,Oligonucleotides ,Humans ,Recombinational DNA Repair ,CRISPR-Cas Systems ,Transfection ,Cell Line - Abstract
Homology-directed genome editing is the intentional alteration of an endogenous genetic locus using information from an exogenous homology donor. A conversion tract is defined as the amount of genetic information that is converted from the homology donor to a given strand of the targeted chromosomal locus. Because of this, conversion tract analysis retrospectively not only elucidates the mechanism of homology-directed genome editing but also provides valuable insights on the conversion efficiency of every nucleotide in the homology donor. Here we describe a blue fluorescent protein-to-green fluorescent protein conversion system that can be conveniently used to measure the efficiency and analyze the lengths of conversion tracts of homology-directed genome editing using oligonucleotide donors in mammalian cells.
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- 2019
13. Conversion Tract Analysis of Homology-Directed Genome Editing Using Oligonucleotide Donors
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Yinan Kan and Eric A. Hendrickson
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chemistry.chemical_classification ,0303 health sciences ,Oligonucleotide ,Locus (genetics) ,Computational biology ,Biology ,Homology (biology) ,03 medical and health sciences ,0302 clinical medicine ,Genome editing ,chemistry ,Fluorescent protein ,Nucleotide ,Gene conversion ,030217 neurology & neurosurgery ,030304 developmental biology - Abstract
Homology-directed genome editing is the intentional alteration of an endogenous genetic locus using information from an exogenous homology donor. A conversion tract is defined as the amount of genetic information that is converted from the homology donor to a given strand of the targeted chromosomal locus. Because of this, conversion tract analysis retrospectively not only elucidates the mechanism of homology-directed genome editing but also provides valuable insights on the conversion efficiency of every nucleotide in the homology donor. Here we describe a blue fluorescent protein-to-green fluorescent protein conversion system that can be conveniently used to measure the efficiency and analyze the lengths of conversion tracts of homology-directed genome editing using oligonucleotide donors in mammalian cells.
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- 2019
14. SUCCESSFUL LONG-TERM TMA- AND REJECTION-FREE SURVIVAL OF A KIDNEY XENOGRAFT WITH TRIPLE XENOANTIGEN KNOCKOUT PLUS INSERTION OF MULTIPLE HUMAN TRANSGENES
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Wenning Qin, Hajime Sasaki, David D.F. Ma, Takayuki Hirose, William F. Westlin, Yinan Kan, Ivy A. Rosales, J. Markmann, Michele Youd, Luhan Yang, Robert B. Colvin, Jacob V. Layer, and Tatsuo Kawai
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Transplantation ,Kidney ,medicine.anatomical_structure ,Transgene ,medicine ,Cancer research ,Biology ,Term (time) - Published
- 2020
15. GENETIC MODIFICATIONS ATTENUATE BUT DON’T ABROGATE THE SIALOADHESIN-DEPENDENT ADHESION OF HUMAN RBC TO PORCINE MACROPHAGES
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Lars Burdorf, Ben Cerel, Richard N. Pierson, Margaret R. Connolly, Michele Youd, Yinan Kan, Diogo M. Magnani, Kaitlyn Petitpas, Agnes Azimzadeh, Jacob V. Layer, Zahra Abady, William F. Westlin, and Wenning Qin
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Transplantation ,Chemistry ,Sialoadhesin ,Adhesion ,Cell biology - Published
- 2020
16. PROLONGED SURVIVAL AND ATTENUATED PULMONARY VASCULAR RESISTANCE RISE IN A MULTITRANSGENIC PIG EX VIVO LUNG XENOPERFUSION MODEL
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Agnes Azimzadeh, Madelyn Ma, Zahra Abady, Wenning Qin, Richard N. Pierson, Jacob V. Layer, Aspen Pierson, Margaret R. Connolly, Luhan Yang, Shannon Pratts, Michele Youd, Kaitlyn Petitpas, Yinan Kan, Lars Burdorf, and William F. Westlin
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Transplantation ,Pathology ,medicine.medical_specialty ,medicine.anatomical_structure ,Lung ,business.industry ,Vascular resistance ,medicine ,business ,Ex vivo - Published
- 2020
17. PROLONGED SURVIVAL OF GENETICALLY MODIFIED PIG LIVERS DURING MACHINE PERFUSION WITH HUMAN BLOOD
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William F. Westlin, James F. Markmann, Taylor M. Coe, Ivy A. Rosales, Wenning Qin, Rudy Matheson, Cailah Carroll, Luhan Yang, Nikolaos Serifis, Agnes Azimzadeh, Michele Youd, Charles G. Rickert, Shoko Kimura, Jacob V. Layer, Siavash Raigani, Yinan Kan, and Danielle Detelich
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Andrology ,Transplantation ,Machine perfusion ,Human blood ,Biology ,Genetically modified organism - Published
- 2020
18. GENETIC MODIFICATIONS OF THE PORCINE GENOME REGULATE INFLAMMATORY AND COAGULATION RESPONSES DURING EX-VIVO PORCINE LIVER PERFUSION WITH HUMAN BLOOD
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Gulcin Demirci, James F. Markmann, Yinan Kan, Rudy Matheson, Jacob V. Layer, Agnes Azimzadeh, Charles G. Rickert, Taylor M. Coe, Nikolaos Serifis, Wenning Qin, Michele Youd, William F. Westlin, Danielle Detelich, Cailah Carroll, and Luhan Yang
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Transplantation ,Pathology ,medicine.medical_specialty ,Coagulation ,Human blood ,business.industry ,Porcine liver ,medicine ,business ,Genome ,Perfusion ,Ex vivo - Published
- 2020
19. Corrigendum: Engineering and optimising deaminase fusions for genome editing
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Luhan, Yang, Adrian W, Briggs, Wei Leong, Chew, Prashant, Mali, Marc, Guell, John, Aach, Daniel Bryan, Goodman, David, Cox, Yinan, Kan, Emal, Lesha, Venkataramanan, Soundararajan, Feng, Zhang, and George, Church
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Article - Abstract
Precise editing is essential for biomedical research and gene therapy. Yet, homology-directed genome modification is limited by the requirements for genomic lesions, homology donors and the endogenous DNA repair machinery. Here we engineered programmable cytidine deaminases and test if we could introduce site-specific cytidine to thymidine transitions in the absence of targeted genomic lesions. Our programmable deaminases effectively convert specific cytidines to thymidines with 13% efficiency in Escherichia coli and 2.5% in human cells. However, off-target deaminations were detected more than 150 bp away from the target site. Moreover, whole genome sequencing revealed that edited bacterial cells did not harbour chromosomal abnormalities but demonstrated elevated global cytidine deamination at deaminase intrinsic binding sites. Therefore programmable deaminases represent a promising genome editing tool in prokaryotes and eukaryotes. Future engineering is required to overcome the processivity and the intrinsic DNA binding affinity of deaminases for safer therapeutic applications., Precision genome engineering using homology donors and the endogenous DNA break repair machinery and recently CRISPR-Cas9 targeted APOBECs have been demonstrated. Here the authors design zinc-finger and TALE chimeric deaminases and investigate editing efficiency and off-target effects.
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- 2017
20. Correction: Corrigendum: Engineering and optimising deaminase fusions for genome editing
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Yinan Kan, George M. Church, John Aach, Daniel B. Goodman, Venkataramanan Soundararajan, Feng Zhang, Wei Leong Chew, Emal Lesha, David Benjamin Turitz Cox, Prashant Mali, Adrian W. Briggs, Luhan Yang, and Marc Güell
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0301 basic medicine ,Genetics ,Multidisciplinary ,Science ,030232 urology & nephrology ,General Physics and Astronomy ,General Chemistry ,Biology ,General Biochemistry, Genetics and Molecular Biology ,World Wide Web ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Email address ,Genome editing ,GEORGE (programming language) - Abstract
Nature Communications 7: Article number: 13330 (2016); Published 2 November 2016; Updated 9 October 2017. The original version of this Article contained an error in the email address of the corresponding author George Church. The correct email is gchurch@genetics.med.harvard.edu. The error has been corrected in the HTML and PDF versions of the Article.
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- 2017
21. FANCI and FANCD2 have common as well as independent functions during the cellular replication stress response
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Maya Raghunandan, Elizabeth L. Thompson, Constanze Wiek, Orlando D. Schärer, Eun A. Lee, Jung E. Yeo, Eric A. Hendrickson, Helmut Hanenberg, Yinan Kan, and Alexandra Sobeck
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0301 basic medicine ,DNA Replication ,congenital, hereditary, and neonatal diseases and abnormalities ,DNA Repair ,DNA repair ,Immunoblotting ,RAD51 ,Medizin ,Biology ,Origin of replication ,medicine.disease_cause ,03 medical and health sciences ,Fanconi anemia ,hemic and lymphatic diseases ,Sequence Homology, Nucleic Acid ,FANCD2 ,Genetics ,medicine ,Humans ,DNA Breaks, Double-Stranded ,Molecular Biology ,Cell Proliferation ,Cell Nucleus ,Mutation ,Base Sequence ,Fanconi Anemia Complementation Group D2 Protein ,Cell Cycle ,DNA replication ,nutritional and metabolic diseases ,medicine.disease ,HCT116 Cells ,Chromatin ,Fanconi Anemia Complementation Group Proteins ,Cell biology ,030104 developmental biology ,Rad51 Recombinase - Abstract
Fanconi anemia (FA) is an inherited cancer predisposition syndrome characterized by cellular hypersensitivity to DNA interstrand crosslinks (ICLs). To repair these lesions, the FA proteins act in a linear hierarchy: following ICL detection on chromatin, the FA core complex monoubiquitinates and recruits the central FANCI and FANCD2 proteins that subsequently coordinate ICL removal and repair of the ensuing DNA double-stranded break by homology-dependent repair (HDR). FANCD2 also functions during the replication stress response by mediating the restart of temporarily stalled replication forks thereby suppressing the firing of new replication origins. To address if FANCI is also involved in these FANCD2-dependent mechanisms, we generated isogenic FANCI-, FANCD2- and FANCI:FANCD2 double-null cells. We show that FANCI and FANCD2 are partially independent regarding their protein stability, nuclear localization and chromatin recruitment and contribute independently to cellular proliferation. Simultaneously, FANCD2—but not FANCI—plays a major role in HDR-mediated replication restart and in suppressing new origin firing. Consistent with this observation, deficiencies in HDR-mediated DNA DSB repair can be overcome by stabilizing RAD51 filament formation in cells lacking functional FANCD2. We propose that FANCI and FANCD2 have partially non-overlapping and possibly even opposing roles during the replication stress response.
- Published
- 2017
22. Inactivation of porcine endogenous retrovirus in pigs using CRISPR-Cas9
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Heng Zhao, Gang Wang, Yonglun Luo, Emal Lesha, Deling Jiao, Yinan Kan, Ellen Shrock, George M. Church, Hong-Jiang Wei, Yong Wang, Hong Wei, I-Hsiu Lee, Marc Güell, Dong Niu, Shouqi Wang, Xiaoyang Zhou, Haydy George, Tao Wang, Lin Lin, Yubo Qing, Hong-Ye Zhao, and Luhan Yang
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0301 basic medicine ,Swine ,Xenotransplantation ,medicine.medical_treatment ,Sus scrofa ,Transplantation, Heterologous ,Endogenous retrovirus ,030230 surgery ,Biology ,Article ,03 medical and health sciences ,0302 clinical medicine ,Genome editing ,Disease Transmission, Infectious ,medicine ,Journal Article ,CRISPR ,Animals ,Humans ,Malalties transmissibles ,health care economics and organizations ,Silenciament gènic ,Gene Editing ,Multidisciplinary ,HEK 293 cells ,Endogenous Retroviruses ,Virology ,Xenotrasplantament ,Transplantation ,HEK293 Cells ,030104 developmental biology ,Cell culture ,Somatic cell nuclear transfer ,CRISPR-Cas Systems ,Retroviridae Infections - Abstract
Xenotransplantation is a promising strategy to alleviate the shortage of organs for human transplantation. In addition to the concerns about pig-to-human immunological compatibility, the risk of cross-species transmission of porcine endogenous retroviruses (PERVs) has impeded the clinical application of this approach. We previously demonstrated the feasibility of inactivating PERV activity in an immortalized pig cell line. We now confirm that PERVs infect human cells, and we observe the horizontal transfer of PERVs among human cells. Using CRISPR-Cas9, we inactivated all of the PERVs in a porcine primary cell line and generated PERV-inactivated pigs via somatic cell nuclear transfer. Our study highlights the value of PERV inactivation to prevent cross-species viral transmission and demonstrates the successful production of PERV-inactivated animals to address the safety concern in clinical xenotransplantation. This study is mainly funded by eGenesis Inc. and was funded by NIH grant P50 HG005550. Y.L. was funded by Danish Research Council for Independent Research (DFF-1337-00128) and Sapere Aude Young Research Talent Prize (DFF-1335-00763). M.G. was funded by a Human Frontiers Science Program Long Term fellowship. Some of the pig production was funded by Major Program on Basic Research Projects of Yunnan Province, China (Grant No. 2014FC006). PERV elements genotyping illumina miseq data have been uploaded to the European Nucleotide Archive (ENA) hosted by the European Bioinformatics Institute (EBI) with the submission reference PRJEB11222
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- 2017
23. Genome Editing With Targeted Deaminases
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Emal Lesha, Adrian W. Briggs, Wei Leong Chew, John Aach, Daniel B. Goodman, Venkataramanan Soundararajan, David G. Cox, Luhan Yang, Marc Güell, Prashant Mali, Feng Zhang, Yinan Kan, and George M. Church
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Genetics ,Genetic enhancement ,Cytidine ,Biology ,medicine.disease_cause ,chemistry.chemical_compound ,Genome editing ,chemistry ,medicine ,Stem cell ,Thymidine ,Escherichia coli ,Function (biology) ,DNA - Abstract
Precise genetic modifications are essential for biomedical research and gene therapy. Yet, traditional homology-directed genome editing is limited by the requirements for DNA cleavage, donor DNA template and the endogenous DNA break-repair machinery. Here we present programmable cytidine deaminases that enable site-specific cytidine to thymidine (C-to-T) genomic edits without the need for DNA cleavage. Our targeted deaminases are efficient and specific in Escherichia coli, converting a genomic C-to-T with 13% efficiency and 95% accuracy. Edited cells do not harbor unintended genomic abnormalities. These novel enzymes also function in human cells, leading to a site-specific C-to-T transition in 2.5% of cells with reduced toxicity compared with zinc-finger nucleases. Targeted deaminases therefore represent a platform for safer and effective genome editing in prokaryotes and eukaryotes, especially in systems where DSBs are toxic, such as human stem cells and repetitive elements targeting.
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- 2016
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24. PERV inactivation is necessary to guarantee absence of pig-to-patient PERVs transmission in xenotransplantation
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Dong Niu, Gang Wang, Haydy George, Marc Güell, Luhan Yang, Tao Wang, I-Hsiu Lee, Yinan Kan, and George M. Church
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0301 basic medicine ,Transplantation ,Swine ,Xenotransplantation ,medicine.medical_treatment ,Endogenous Retroviruses ,Transplantation, Heterologous ,Immunology ,030230 surgery ,Biology ,Virology ,law.invention ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Transmission (mechanics) ,law ,medicine ,Animals ,Heterografts ,Humans - Published
- 2017
25. A role for XLF in DNA repair and recombination in human somatic cells
- Author
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Junghun Kweon, Yongbao Wang, Eric A. Hendrickson, Farjana J. Fattah, Yinan Kan, Natalie Weisensel, Natalie Lichter, and Eu Han Lee
- Subjects
DNA End-Joining Repair ,DNA repair ,Cell Survival ,Biology ,LIG4 ,Biochemistry ,Article ,Humans ,Homologous Recombination ,Molecular Biology ,chemistry.chemical_classification ,DNA ligase ,Genome, Human ,Point mutation ,V(D)J recombination ,Gene targeting ,Cell Biology ,HCT116 Cells ,Molecular biology ,V(D)J Recombination ,Non-homologous end joining ,DNA-Binding Proteins ,Protein Transport ,DNA Repair Enzymes ,chemistry ,Homologous recombination - Abstract
Classic non-homologous end-joining (C-NHEJ) is required for the repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian cells and plays a critical role in lymphoid V(D)J recombination. A core C-NHEJ component is the DNA ligase IV co-factor, Cernunnos/XLF (hereafter XLF). In patients, mutations in XLF cause predicted increases in radiosensitivity and deficits in immune function, but also cause other less well-understood pathologies including neural disorders. To characterize XLF function(s) in a defined genetic system, we used a recombinant adeno-associated virus-mediated gene targeting strategy to inactivate both copies of the XLF locus in the human HCT116 cell line. Analyses of XLF-null cells (which were viable) showed that they were highly sensitive to ionizing radiation and a radiomimetic DNA damaging agent, etoposide. XLF-null cells had profound DNA DSB repair defects as measured by in vivo plasmid end-joining assays and were also dramatically impaired in their ability to form either V(D)J coding or signal joints on extrachromosomal substrates. Thus, our somatic XLF-null cell line recapitulates many of the phenotypes expected from XLF patient cell lines. Subsequent structure:function experiments utilizing the expression of wild-type and mutant XLF cDNAs demonstrated that all of the phenotypes of an XLF deficiency could be rescued by the overexpression of a wild-type XLF cDNA. Unexpectedly, mutant forms of XLF bearing point mutations at amino acid positions L115 and L179, also completely complemented the null phenotype suggesting, in contrast to predictions to the contrary, that these mutations do not abrogate XLF function. Finally, we demonstrate that the absence of XLF causes a small, but significant, increase in homologous recombination, implicating XLF in DSB pathway choice regulation. We conclude that human XLF is a non-essential, but critical, C-NHEJ-repair factor.
- Published
- 2014
26. A ONE-SHOT SOLUTION TO BACTERIAL AND FUNGAL CONTAMINATION IN THE GREEN ALGA CHLAMYDOMONAS REINHARDTII CULTURE BY USING AN ANTIBIOTIC COCKTAIL1
- Author
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Junmin Pan and Yinan Kan
- Subjects
Cefotaxime ,biology ,Carbendazim ,Chlamydomonas ,Chlamydomonas reinhardtii ,Plant Science ,Aquatic Science ,Contamination ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Ampicillin ,Botany ,medicine ,Bacteria ,Organism ,medicine.drug - Abstract
Keeping sterile stocks or cultures of microalgae is fundamental to microalgae biotechnology as well as basic scientific research. However, contamination by bacteria and/or fungi in microalgae cultures or stocks is often a problem. Here, we have developed a strategy for reducing or eliminating bacterial and fungal contamination by using a cocktail of antibiotics. Chlamydomonas reinhardtii P. A. Dang., a widely used unicellular green alga, has been used as a testing organism. A combination of ampicillin, cefotaxime, and carbendazim removed or reduced contamination by three different bacteria and two different fungi tested. A step-by-step procedure is provided, which is simple, economical, and effective.
- Published
- 2010
27. FANCI and FANCD2 have common as well as independent functions during the cellular replication stress response.
- Author
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Thompson, Elizabeth L., Yeo, Jung E., Lee, Eun-A, Yinan Kan, Raghunandan, Maya, Wiek, Constanze, Hanenberg, Helmut, Schärer, Orlando D., Hendrickson, Eric A., and Sobeck, Alexandra
- Published
- 2017
- Full Text
- View/download PDF
28. Inactivation of porcine endogenous retrovirus in pigs using CRISPR-Cas9.
- Author
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Dong Niu, Hong-Jiang Wei, Lin Lin, George, Haydy, Tao Wang, I-Hsiu Lee, Hong-Ye Zhao, Yong Wang, Yinan Kan, Shrock, Ellen, Lesha, Emal, Gang Wang, Yonglun Luo, Yubo Qing, Deling Jiao, Heng Zhao, Xiaoyang Zhou, Shouqi Wang, Hong Wei, and Güell, Marc
- Published
- 2017
- Full Text
- View/download PDF
29. The HSV-1 Exonuclease, UL12, Stimulates Recombination by a Single Strand Annealing Mechanism
- Author
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Jeremy M. Stark, Yinan Kan, Kareem N. Mohni, April J. Schumacher, Eric A. Hendrickson, and Sandra K. Weller
- Subjects
lcsh:Immunologic diseases. Allergy ,DNA Replication ,Exonuclease ,ICP8 ,DNA repair ,viruses ,Immunology ,DNA, Single-Stranded ,Herpesvirus 1, Human ,Biochemistry ,Microbiology ,Viral Proteins ,Virology ,Molecular Cell Biology ,Genetics ,Humans ,Homologous Recombination ,lcsh:QH301-705.5 ,Biology ,Molecular Biology ,Deoxyribonucleases ,biology ,DNA replication ,Herpes Simplex ,Molecular biology ,Double Strand Break Repair ,Rad52 DNA Repair and Recombination Protein ,DNA-Binding Proteins ,Non-homologous end joining ,HEK293 Cells ,lcsh:Biology (General) ,Rolling circle replication ,DNA, Viral ,biology.protein ,Parasitology ,lcsh:RC581-607 ,Homologous recombination ,Research Article - Abstract
Production of concatemeric DNA is an essential step during HSV infection, as the packaging machinery must recognize longer-than-unit-length concatemers; however, the mechanism by which they are formed is poorly understood. Although it has been proposed that the viral genome circularizes and rolling circle replication leads to the formation of concatemers, several lines of evidence suggest that HSV DNA replication involves recombination-dependent replication reminiscent of bacteriophages λ and T4. Similar to λ, HSV-1 encodes a 5′-to-3′ exonuclease (UL12) and a single strand annealing protein [SSAP (ICP8)] that interact with each other and can perform strand exchange in vitro. By analogy with λ phage, HSV may utilize viral and/or cellular recombination proteins during DNA replication. At least four double strand break repair pathways are present in eukaryotic cells, and HSV-1 is known to manipulate several components of these pathways. Chromosomally integrated reporter assays were used to measure the repair of double strand breaks in HSV-infected cells. Single strand annealing (SSA) was increased in HSV-infected cells, while homologous recombination (HR), non-homologous end joining (NHEJ) and alternative non-homologous end joining (A-NHEJ) were decreased. The increase in SSA was abolished when cells were infected with a viral mutant lacking UL12. Moreover, expression of UL12 alone caused an increase in SSA, which was completely eliminated when a UL12 mutant lacking exonuclease activity was expressed. UL12-mediated stimulation of SSA was decreased in cells lacking the cellular SSAP, Rad52, and could be restored by coexpressing the viral SSAP, ICP8, indicating that an SSAP is also required. These results demonstrate that UL12 can specifically stimulate SSA and that either ICP8 or Rad52 can function as an SSAP. We suggest that SSA is the homology-mediated repair pathway utilized during HSV infection., Author Summary The repair of DNA damage is essential to maintain genomic stability. Cells have at least four distinct DNA repair pathways, and defects in any of them can lead to tumor formation and cancer progression. Herpes Simplex Virus-1 (HSV-1) manipulates components of the host DNA repair pathways. In this paper we showed that DNA repair by the single strand annealing (SSA) pathway was increased during HSV infection and that other pathways were inhibited. We also show that a viral nuclease in conjunction with either a viral or cellular single strand annealing protein can stimulate the SSA pathway. We suggest that viral DNA synthesis occurs via an SSAdependent mechanism that is reminiscent of that used by bacterial viruses such as λ. Interestingly, λ has evolved an SSA-mediated repair mechanism to exchange genetic information that has also been used to enhance gene targeting in bacteria. It is thus possible that HSV proteins could be similarly used as tools to stimulate gene targeting in human cells leading to more effective strategies for gene therapy. Furthermore, the diversity of HSV reported in human populations, combined with the high rate of genetic exchange during infection, suggests that SSA may play a role in viral evolution and pathogenesis.
- Published
- 2012
30. The HSV-1 Exonuclease, UL12, Stimulates Recombination by a Single Strand Annealing Mechanism.
- Author
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Schumacher, April J., Mohni, Kareem N., Yinan Kan, Hendrickson, Eric A., Stark, Jeremy M., and Weller, Sandra K.
- Subjects
EXONUCLEASES ,HERPES simplex virus ,DNA replication ,BACTERIOPHAGES ,EUKARYOTIC cells - Abstract
Production of concatemeric DNA is an essential step during HSV infection, as the packaging machinery must recognize longer-than-unit-length concatemers; however, the mechanism by which they are formed is poorly understood. Although it has been proposed that the viral genome circularizes and rolling circle replication leads to the formation of concatemers, several lines of evidence suggest that HSV DNA replication involves recombination-dependent replication reminiscent of bacteriophages l and T4. Similar to l, HSV-1 encodes a 59-to-39 exonuclease (UL12) and a single strand annealing protein [SSAP (ICP8)] that interact with each other and can perform strand exchange in vitro. By analogy with l phage, HSV may utilize viral and/or cellular recombination proteins during DNA replication. At least four double strand break repair pathways are present in eukaryotic cells, and HSV-1 is known to manipulate several components of these pathways. Chromosomally integrated reporter assays were used to measure the repair of double strand breaks in HSV-infected cells. Single strand annealing (SSA) was increased in HSV-infected cells, while homologous recombination (HR), non-homologous end joining (NHEJ) and alternative non-homologous end joining (A-NHEJ) were decreased. The increase in SSA was abolished when cells were infected with a viral mutant lacking UL12. Moreover, expression of UL12 alone caused an increase in SSA, which was completely eliminated when a UL12 mutant lacking exonuclease activity was expressed. UL12-mediated stimulation of SSA was decreased in cells lacking the cellular SSAP, Rad52, and could be restored by coexpressing the viral SSAP, ICP8, indicating that an SSAP is also required. These results demonstrate that UL12 can specifically stimulate SSA and that either ICP8 or Rad52 can function as an SSAP. We suggest that SSA is the homology-mediated repair pathway utilized during HSV infection. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
31. The Phosphorylation State of an Aurora-Like Kinase Marks the Length of Growing Flagella in Chlamydomonas
- Author
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Guihua Li, William J. Snell, Muqing Cao, Yinan Kan, Minna Luo, and Junmin Pan
- Subjects
Immunoblotting ,Protein Serine-Threonine Kinases ,Flagellum ,General Biochemistry, Genetics and Molecular Biology ,Article ,Dephosphorylation ,Aurora Kinases ,Intraflagellar transport ,Organelle ,Phosphorylation ,Protein kinase A ,Body Patterning ,Plant Proteins ,Agricultural and Biological Sciences(all) ,biology ,Biochemistry, Genetics and Molecular Biology(all) ,Cilium ,Chlamydomonas ,biology.organism_classification ,Cell biology ,Flagella ,General Agricultural and Biological Sciences ,Protein Processing, Post-Translational ,Signal Transduction - Abstract
Summary Flagella and cilia are structurally polarized organelles whose lengths are precisely defined, and alterations in length are related to several human disorders [1, 2]. Intraflagellar transport (IFT) and protein signaling molecules are implicated in specifying flagellar and ciliary length [3–6], but evidence has been lacking for a flagellum and cilium length sensor that could participate in active length control or establishment of structural polarity. Previously, we showed that the phosphorylation state of the aurora-like protein kinase CALK in Chlamydomonas is a marker of the absence of flagella. Here we show that CALK phosphorylation state is also a marker for flagellar length. CALK is phosphorylated in cells without flagella, and during flagellar assembly it becomes dephosphorylated. Dephosphorylation is not simply a consequence of initiation of flagellar assembly or of time after experimentally induced flagellar loss, but instead requires flagella to be assembled to a threshold length. Analysis of cells with flagella of varying lengths shows that the threshold length for CALK dephosphorylation is ∼6 μm (half length). Studies with short and long flagellar mutants indicate that cells detect absolute rather than relative flagellar length. Our results demonstrate that cells possess a mechanism for translating flagellar length into a posttranslational modification of a known flagellar regulatory protein.
- Full Text
- View/download PDF
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