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Masakazu Ichinose,1 Masaharu Nishimura,2 Manabu Akimoto,3 Yasuhiro Kurotori,3 Yihua Zhao,4 Alberto de la Hoz,5 Michiaki Mishima6 1Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; 2Department of Pulmonary Medicine, Faculty School of Medicine, Hokkaido University, Sapporo, Japan; 3Nippon Boehringer Ingelheim Co. Ltd, Tokyo, Japan; 4Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA; 5Boehringer Ingelheim International GmbH, Ingelheim, Germany; 6Osaka Saiseikai Noe Hospital, Osaka, Japan Background: The DYNAGITO study was a Phase IIIb, randomized, double-blind, multicenter, active-controlled, parallel-group, 52-week study designed to determine the efficacy and safety of tiotropium and olodaterol combination therapy (TIO+OLO 5/5 μg) versus tiotropium monotherapy (TIO 5 μg) for reducing moderate-to-severe exacerbations of COPD. This is a prespecified analysis of the DYNAGITO data in Japanese patients. Patients and methods: Enrolled patients had a diagnosis of COPD with at least one moderate-to-severe exacerbation in the previous 12 months. Of the total 7,880 treated patients in the DYNAGITO study, 461 (TIO+OLO 5/5 μg: n=226, TIO 5 μg: n=235) were Japanese. The primary endpoint was the annualized rate of moderate-to-severe COPD exacerbations. The key secondary endpoint was the time to first moderate-to-severe COPD exacerbation, and other secondary endpoints included the annualized rate of exacerbations leading to hospitalization, time to first COPD exacerbation leading to hospitalization, and all-cause mortality. Safety data were analyzed descriptively. Results: Combination therapy with TIO+OLO resulted in a 29% lower rate of moderate-to-severe COPD exacerbations relative to TIO monotherapy (rate ratio 0.71; 99% CI: 0.46, 1.10; p=0.0434). The risk of a first moderate-to-severe COPD exacerbation was 19% lower with TIO+OLO combination therapy than with TIO monotherapy (HR 0.81; 99% CI: 0.57, 1.17; p=0.1379), although this difference was not statistically significant. The annualized rate of COPD exacerbations requiring hospitalization was 14% lower in the TIO+OLO arm than in the TIO arm (rate ratio 0.86; 95% CI: 0.52, 1.42; p=0.5654). The adverse event incidence was balanced between treatment arms. Conclusion: In a prespecified subgroup analysis of Japanese patients in the DYNAGITO study, combination therapy with TIO+OLO was more effective than TIO in reducing exacerbations. Both treatments were well tolerated. Keywords: all-cause mortality, COPD, fixed-dose combination therapy, hospitalization, moderate-to-severe exacerbations, monotherapy

Background Omalizumab, a humanized anti- Ig E monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum Ig E levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. Methods In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum Ig E levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. Results We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum Ig E levels after 16 or 32 weeks of treatment. Reduced free serum Ig E levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum Ig E levels. Conclusion Baseline serum periostin levels and serum free Ig E levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment. [ABSTRACT FROM AUTHOR]

Telomerase reverse transcriptase (TERT) gene aberration is detectable in >80% of cases with hepatocellular carcinoma (HCC). TERT reactivation is essential for cellular immortalization because it stabilizes telomere length, although the role of TERT in hepatocarcinogenesis remains unelucidated. To elucidate the significance of aberrant TERT expression in hepatocytes in inflammation-associated hepatocarcinogenesis, we generated Alb-Cre;TertTg mice, which overexpress TERT in the liver and examined their phenotype during chronic inflammation. Based on transcriptome data from the liver tissue of Alb-Cre;TertTg mice, we examined the role of TERT in hepatocarcinogenesis in vitro. We also evaluated the relationship between TERT and cell-cycle-related molecules, including p21, in HCC samples. The liver tumor development rate was increased by TERT overexpression during chronic inflammation, especially in the absence of p53 function. Gene set enrichment analysis of liver tissues revealed that gene sets related to TNF-NFκB signaling, cell cycle, and apoptosis were upregulated in Alb-Cre;TertTg liver. A luciferase reporter assay and immunoprecipitation revealed that TERT interacted with NFκB p65 and enhanced NFκB promoter activity. On the other hand, TERT formed protein complexes with p21, cyclin A2, and cyclin E and promoted ubiquitin-mediated degradation of p21, specifically in the G1 phase. In the clinical HCC samples, TERT was highly expressed but p21 was conversely downregulated, and TERT expression was associated with the upregulation of molecules related to the cell cycle. Taken together, the aberrant upregulation of TERT increased NFκB promoter activity and promoted cell cycle progression via p21 ubiquitination, leading to hepatocarcinogenesis. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland., (© 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

Dietary proteins serve as sources of exogenous peptides, after being released from the protein and absorbed, the bioactive peptides can perform several functions in the body. The objective of the current systematic review is to answer the question "How does food derived bioactive peptides can impact on gut health and inflammatory mediators in vivo?" The search was performed at PubMed, Cochrane, and Scopus databases for experimental studies, and the risk of bias was assessed by the SYRCLE tool. The data analysis was conducted following the PRISMA guidelines. Eleven studies performed in animal models evaluating bioactive peptides derived from animal and plant sources were included and evaluated for limitations in heterogeneity, methodologies, absence of information regarding the allocation process, and investigators' blinding. The bioactive peptides demonstrated potential positive effects on inflammation and gut health. The main results identified were a reduction in TNF-α, NF-κB, and TLR4, an improvement in IgA production and in intestinal morphology, with an increase in villi surface area and goblet cell diameter, and Shannon and Simpson indexes were also increased. However, more in vivo studies are still necessary to better elucidate the anti-inflammatory activity and mechanisms by which peptides regulate gut health. PROSPERO (CRD42023416680).

CYP3A4 and CYP3A5 are the most abundant and important enzymes of the CYP3A subfamily, distributed in the liver, intestinal mucosa and kidney, and involved in tacrolimus metabolism. Here, we report a case of tacrolimus dosage refractoriness due to a genetic polymorphism of CYP3A5., Competing Interests: The authors state that the study was conducted without any commercial or financial relationships that could be interpreted as a conflict of interest., (© 2024 The Author(s). Clinical Case Reports published by John Wiley & Sons Ltd.)

Deprotonation or suppression of the p K a of the amino group of a lysine sidechain is a widely recognized phenomenon whereby the sidechain amino group transiently can act as a nucleophile at the active site of enzymatic reactions. However, a deprotonated lysine and its molecular interactions have not been directly experimentally detected. Here, we demonstrate a deprotonated lysine stably serving as an "acceptor" in a H-bond between the photosensor protein RcaE and its chromophore. Signal splitting and trans-H-bond J coupling observed by NMR spectroscopy provide direct evidence that Lys261 is deprotonated and serves as a H-bond acceptor for the chromophore NH group. Quantum mechanical/molecular mechanical calculations also indicate that this H-bond exists stably. Interestingly, the sidechain amino group of the lysine can act as both donor and acceptor. The remarkable shift in the H-bond characteristics arises from a decrease in solvation, triggered by photoisomerization. Our results provide insights into the dual role of this lysine. This mechanism has broad implications for other biological reactions in which lysine plays a role., Competing Interests: Competing interests statement:The authors declare no competing interest.

StayGold is an exceptionally bright and stable fluorescent protein that is highly resistant to photobleaching. Despite favorable fluorescence properties, use of StayGold as a fluorescent tag is limited because it forms a natural dimer. Here we report the 1.6 Å structure of StayGold and generate a derivative, mStayGold, that retains the brightness and photostability of the original protein while being fully monomeric., (© 2023. The Author(s).)

Reproductive toxicity is one of the major concerns in drug development. Thus, we have developed its screening system using Caenorhabditis elegans, which has a life cycle of three days and similar coding genes as humans. Antiviral nucleoside analogs used for acute infections are known to cause reproductive toxicity, contraindicated for pregnant women, and are used for comparing their reproductive toxicity in C. elegans and experimental animals. None of the drug treatments affected the number of offspring and the concentrations without toxicity to nematodes were consistent with no cytotoxicity or toxicity in experimental animals or humans. Favipiravir, ribavirin, molnupiravir (NHC), acyclovir, ganciclovir, zidovudine, and thalidomide significantly increased the incidence of arrested embryos but amenamevir, letermovir, and guanosine did not. RNA-dependent RNA polymerase (RdRp) inhibitors, in the order of favipiravir, ribavirin, and NHC increased the incidence of arrested embryos, possibly due to the specificity of favipiravir for RdRp and less cytotoxicity. RdRp inhibitors would impair RNA interference through RdRp expressed by telomerase reverse transcriptase during embryogenesis and cause embryo-fetal toxicity. The incidence of arrested embryos may be affected by differences in the substrate specificity of DNA polymerases and metabolism between C. elegans , animals, and humans. The concordance between the results of the screening system for reproductive toxicity of antivirals in C. elegans and those in experimental animals based on the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use, reproductive toxicology confirms its appropriateness as a screening system for reproductive toxicity. Favipiravir and zidovudine were the least toxic to C. e legans among the antiviral drugs examined., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Certain cyanobacteria alter their photosynthetic light absorption between green and red, a phenomenon called complementary chromatic acclimation. The acclimation is regulated by a cyanobacteriochrome-class photosensor that reversibly photoconverts between green-absorbing (Pg) and red-absorbing (Pr) states. Here, we elucidated the structural basis of the green/red photocycle. In the Pg state, the bilin chromophore adopted the extended C15- Z , anti structure within a hydrophobic pocket. Upon photoconversion to the Pr state, the bilin is isomerized to the cyclic C15- E , syn structure, forming a water channel in the pocket. The solvation/desolvation of the bilin causes changes in the protonation state and the stability of π-conjugation at the B ring, leading to a large absorption shift. These results advance our understanding of the enormous spectral diversity of the phytochrome superfamily.

Carotenoids have anti-inflammatory and antioxidant properties, being a potential bioactive compound for gut health. The objective of this systematic review was to investigate the effects of carotenoids on gut microbiota, gut barrier, and inflammation in healthy animals. The systematic search from PubMed, Scopus, and Lilacs databases were performed up to March 2023. The final screening included thirty studies, with different animal models (mice, rats, pigs, chicks, drosophila, fish, and shrimp), and different carotenoid sources (β-carotene, lycopene, astaxanthin, zeaxanthin, lutein, and fucoxanthin). The results suggested that carotenoids seem to act on gut microbiota by promoting beneficial effects on intestinal bacteria related to both inflammation and SCFA production; increase tight junction proteins expression, important for reducing intestinal permeability; increase the mucins expression, important in protecting against pathogens and toxins; improve morphological parameters important for digestion and absorption of nutrients; and reduce pro-inflammatory and increase anti-inflammatory cytokines. However, different carotenoids had distinct effects on gut health. In addition, there was heterogeneity between studies regarding animal model, duration of intervention, and doses used. This is the first systematic review to address the effects of carotenoids on gut health. Further studies are needed to better understand the effects of carotenoids on gut health.

Effective early-stage markers for predicting which patients are at risk of developing SARS-CoV-2 infection have not been fully investigated. Here, we performed comprehensive serum metabolome analysis of a total of 83 patients from two cohorts to determine that the acceleration of amino acid catabolism within 5 days from disease onset correlated with future disease severity. Increased levels of de-aminated amino acid catabolites involved in the de novo nucleotide synthesis pathway were identified as early prognostic markers that correlated with the initial viral load. We further employed mice models of SARS-CoV2-MA10 and influenza infection to demonstrate that such de-amination of amino acids and de novo synthesis of nucleotides were associated with the abnormal proliferation of airway and vascular tissue cells in the lungs during the early stages of infection. Consequently, it can be concluded that lung parenchymal tissue remodeling in the early stages of respiratory viral infections induces systemic metabolic remodeling and that the associated key amino acid catabolites are valid predictors for excessive inflammatory response in later disease stages., (© 2023. The Author(s).)

Uncertainty principle prohibits the precise measurement of both components of displacement parameters in phase space. We have theoretically shown that this limit can be beaten using single-photon states, in a single-shot and single-mode setting [F. Hanamura et al., Estimation of gaussian random displacement using non-gaussian states, Phys. Rev. A 104, 062601 (2021).PLRAAN2469-992610.1103/PhysRevA.104.062601]. In this Letter, we validate this by experimentally beating the classical limit. In optics, this is the first experiment to estimate both parameters of displacement using non-Gaussian states. This result is related to many important applications, such as quantum error correction.

Objective: Systemic corticosteroid administration, also called short bursts (SB), is harmful for patients with asthma; however, the actual burden of one-day SB remains unsolved. This study aimed to elucidate the characteristics of patients requiring one-day SB against asthma in clinical practice., Methods: Consecutive patients who regularly visited our hospital for asthma treatment between January 2019 and December 2020 were reviewed and followed for one year. SB was defined as ≥3 days of systemic corticosteroid treatment for an exacerbation. One-day SB was defined as one-day of systemic corticosteroid to treat an exacerbation. The one-day SB group included patients who received only one-day SB but no SB during the preceding year. Frequent SB was defined as that occurring ≥2 times/year., Results: Data on 229 patients were analyzed. Among them, 2.6% (95% confidence interval 1.2-5.6%) were in the one-day SB group. The one-day SB group was female-dominant, obese, non-eosinophilic, and non-atopic. The median one-day SB was 1.5 times/year and almost half of one-day SB were performed by patients themselves. Independent of the low pulmonary function, high blood eosinophil count, and inhaled corticosteroid dose, one-day SB was associated with future frequent SB (adjusted odds ratio = 18.2, 95% confidence interval 1.1-288, P  = 0.040, compared to the no SB group)., Conclusions: Although one-day SB was not frequently experienced, even one-day SB without conventional SB was associated with future frequent SB. It is important to grasp the actual condition of one-day SB and to reinforce the treatment used.

Obesity is a global health problem caused by genetic, environmental, and psychological factors and is associated with various health disorders. As such, there is a growing focus on the prevention of obesity and related diseases. The gut microbiota plays a crucial role in these diseases and has become a therapeutic target. Prebiotics, such as poly-d-3-hydroxybutyric acid (PHB), have gained attention for their potential to alter the gut microbiota, promote beneficial bacterial growth, and alleviate obesity. In this study, we examined the prebiotic effects of PHB in obese mice. We found that, in C57BL/6N mice, PHB reduced blood lipid levels. Analysis of the intestinal microflora also revealed an increase in short-chain fatty acid-producing bacteria. When PHB was administered to obese mice, subcutaneous fat and dyslipidemia were reduced, and the number of beneficial bacteria in the intestinal microflora increased. Furthermore, fatty degradation and oxidative stress were suppressed in the liver. PHB regulates gut bacterial changes related to obesity and effectively inhibits dyslipidemia, suggesting that it could be a prebiotic agent for curing various obesity-related diseases. In summary, PHB increases the beneficial gut microbiota, leading to an alleviation of obesity-associated dyslipidemia., (© 2023 Federation of American Societies for Experimental Biology.)

Background: We sometimes experience disinhibition during bronchoscopy with sedation. However, the impact of adding pethidine on disinhibition has not yet been investigated. This study aimed to examine the additive impact of pethidine on disinhibition during bronchoscopy with midazolam., Methods: This retrospective study involved consecutive patients who underwent bronchoscopy between November 2019 and December 2020 (sedated with midazolam: Midazolam group) and between December 2020 and December 2021 (sedated with midazolam plus pethidine: Combination group). The severity of disinhibition was defined as follows: moderate, disinhibition that always needed restraints by assistants; and severe, disinhibition that needed antagonization of sedation by flumazenil to continue bronchoscopy. One-to-one propensity score matching was used to match baseline characteristics between both groups., Results: After propensity score matching with depression, the type of bronchoscopic procedure, and the dose of midazolam, 142 patients matched in each group. The prevalence of moderate-to-severe disinhibition significantly decreased from 16.2% to 7.8% (P = 0.028) in the Combination group. The Combination group had significantly better scores for sensation after bronchoscopy and feelings toward bronchoscopy duration than did the Midazolam group. Although the minimum SpO 2 during bronchoscopy was significantly lower (88.0 ± 6.2 mmHg vs. 86.7 ± 5.0 mmHg, P = 0.047) and the percentage of oxygen supplementation significantly increased (71.1% vs. 86.6%, P = 0.001) in the Combination group, no fatal complications were observed., Conclusions: Adding pethidine could reduce disinhibition occurrence in patients undergoing bronchoscopy with midazolam, with better subjective patient outcomes during and after bronchoscopy. However, whether more patients may need oxygen supplementation and whether hypoxia occurs during bronchoscopy should be considered., Clinical Trial Registration: UMIN000042635., Competing Interests: Conflict of Interest The authors have no conflict of interest., (Copyright © 2023 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.)

Omalizumab can cause hypersensitivity reactions. We herein report the first case of an 18-year-old woman with refractory cough-predominant asthma that correlated with allergic reactions caused by omalizumab and the coronavirus disease 2019 (COVID-19) vaccine. The patient developed angioedema after taking omalizumab. She had previously experienced intense coughing immediately after receiving a COVID-19 vaccine. A skin prick test was positive for polysorbate 20, which was probably the cause of the allergic reactions to omalizumab and the COVID-19 vaccine. Clinicians should check for an allergic reaction, irrespective of its intensity, triggered by polysorbate and be careful when prescribing biologics to patients in order to avoid allergic reactions.

Sense of agency (SoA) refers to the subjective feeling of controlling one's own actions and sensory feedback. The SoA occurs when the predicted feedback matches the actual sensory feedback and is responsible for maintaining behavioral comfort. However, sensorimotor deficits because of illness cause incongruence between prediction and feedback, so the patient loses comfort during actions. Discomfort with actions associated with incongruence may continue robustly (i.e., "not" adaptable) throughout life because of the aftereffects of the disease. However, it is unclear how the SoA modulates when incongruency is experienced, even for a short term. The purpose of this study was to investigate the adaptability of the SoA in healthy participants in sensorimotor tasks for a short term. Participants were divided into congruent and incongruent exposure groups. The experimental task of manipulating the ratio of the self-control of a PC cursor was used to measure the SoA before and after exposure to congruent or incongruent stimuli. The results showed no significant differences between the groups before and after exposure for a short term. The finding that the SoA was not adaptable may assist in guiding the direction of future studies on how to correct incongruence.

Inflammatory bowel disease (IBD) is a chronic persistent intestinal disorder, with ulcerative colitis and Crohn's disease being the most common. However, the physio-pathological development of IBD is still unknown. Therefore, research on the etiology and treatment of IBD has been conducted using a variety of approaches. Short-chain fatty acids such as 3-hydroxybutyrate (3-HB) are known to have various physiological activities. In particular, the production of 3-HB by the intestinal microflora is associated with the suppression of various inflammatory diseases. In this study, we investigated whether poly-D-3-hydroxybutyric acid (PHB), a polyester of 3-HB, is degraded by intestinal microbiota and works as a slow-release agent of 3-HB. Further, we examined whether PHB suppresses the pathogenesis of IBD models. As long as a PHB diet increased 3-HB concentrations in the feces and blood, PHB suppressed weight loss and histological inflammation in a dextran sulfate sodium-induced IBD model. Furthermore, PHB increased the accumulation of regulatory T cells in the rectum without affecting T cells in the spleen. These results indicate that PHB has potential applications in treating diseases related to the intestinal microbiota as a sustained 3-HB donor. We show for the first time that biodegradable polyester exhibits intestinal bacteria-mediated bioactivity toward IBD. The use of bioplastics, which are essential materials for sustainable social development, represents a novel approach to diseases related to dysbiosis, including IBD., (© 2022 The Authors. The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology.)

Therapeutic antibodies sometimes elicit anti-drug antibodies (ADAs) that can affect efficacy and safety. Engineered antibodies that contain artificial amino acid sequences are potentially highly immunogenic, but this is currently difficult to predict. Therefore, it is important to efficiently assess immunogenicity during the development of complex antibody-based formats. Here, we present an in vitro peripheral blood mononuclear cell-based assay that can be used to assess immunogenicity potential within 3 days. This method involves examining the frequency and function of interleukin (IL)-2-secreting CD4 + T cells induced by therapeutic antibodies. IL-2-secreting CD4 + T cells seem to be functionally relevant to the immunogenic potential due to their proliferative activity and the expression of several cytokines. The rates of the donors responding to low and high immunogenic proteins, mAb1, and keyhole limpet hemocyanin were 1.3% and 93.5%, respectively. Seven antibodies with known rates of immunogenicity (etanercept, emicizumab, abciximab, romosozumab, blosozumab, humanized anti-human A33 antibody, and bococizumab) induced responses in 1.9%, 3.8%, 6.4%, 10.0%, 29.2%, 43.8%, and 89.5% of donors, respectively. These data are comparable with ADA incidences in clinical settings. Our results show that this assay can contribute to the swift assessment and mechanistic understanding of the immunogenicity of therapeutic antibodies.

Fc-engineering is commonly used to improve the therapeutic potency of antibody (Ab) treatments. Because FcγRIIb is the only inhibitory FcγR that contains an immunoreceptor tyrosine-based inhibition motif (ITIM), Fc-engineered Abs with enhanced binding affinity to FcγRIIb might provide immune suppression in clinical contexts. GYM329 is an anti-latent myostatin Fc-engineered Ab with increased affinity to FcγRIIb which is expected to improve muscle strength in patients with muscular disorders. Cross-linking of FcγRIIb by immune complex (IC) results in phosphorylation of ITIM to inhibit immune activation and apoptosis in B cells. We examined whether the IC of Fc-engineered Abs with enhanced binding affinity to FcγRIIb causes phosphorylation of ITIM or B cell apoptosis using GYM329 and its Fc variant Abs in human and cynomolgus-monkey (cyno) immune cells in vitro. IC of GYM329 with enhanced binding affinity to human FcγRIIb (×5) induced neither ITIM phosphorylation nor B cell apoptosis. As for GYM329, FcγRIIb should work as an endocytic receptor of small IC to sweep latent myostatin, so it is preferable that GYM329 induces neither ITIM phosphorylation nor B cell apoptosis to prevent immune suppression. In contrast, IC of myo-HuCy2b, the Ab with enhanced binding affinity to human FcγRIIb (×4), induced ITIM phosphorylation and B cell apoptosis. The result of the present study demonstrated that Fc-engineered Abs with similar binding affinity to FcγRIIb had different effects. Thus, it is important to also investigate FcγR-mediated immune functions other than binding to fully understand the biological effects of Fc-engineered Abs.

Drk, a Drosophila homologue of human GRB2, interacts with Sevenless (Sev) receptor via its SH2 domain, while the N- and C-terminal SH3 domains (Drk-NSH3 and Drk-CSH3, respectively) are responsible for the interaction with proline-rich motifs (PRMs) of Son of sevenless (Sos) or Daughter of Sevenless (Dos). Drk-NSH3 on its own has a conformational equilibrium between folded and unfolded states, and the folded state is stabilised by the association with a Sos-derived proline-rich peptide with PxxPxR motif. In contrast, Drk-CSH3 is supposed to bind PxxxRxxKP motifs in Dos. Aiming at clarifying the structural and functional differences between the two SH3 domains, we performed NMR studies of Drk-CSH3. The resulting solution structure and the 15 N-relaxation data showed that Drk-CSH3 consists of a stable domain. Large chemical shift perturbation was commonly found around the RT loop and the hydrophobic patch, while there were also changes that occur characteristically for Sos- or Dos-derived peptides. Sos-derived two peptides with PxxPxR motif showed stronger affinity to Drk-CSH3, indicating that the Sos PRMs can bind both N- and C-SH3 domains. Dos-derived two peptides could also bind Drk-CSH3, but with much weaker affinity, suggesting a possibility that any cooperative binding of Dos-PRMs may strengthen the Drk-Dos interaction. The NMR studies as well as the docking simulations provide valuable insights into the biological and biophysical functions of two SH3 domains in Drk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Tropomyosins are structurally conserved α-helical coiled-coil proteins that bind along the length of filamentous actin (F-actin) in fungi and animals. Tropomyosins play essential roles in the stability of actin filaments and in regulating myosin II contractility. Despite the crucial role of tropomyosin in actin cytoskeletal regulation, in vivo investigations of tropomyosin are limited, mainly due to the suboptimal live-cell imaging tools currently available. Here, we report on an mNeonGreen (mNG)-tagged tropomyosin, with native promoter and linker length configuration, that clearly reports tropomyosin dynamics in Schizosaccharomyces pombe (Cdc8), Schizosaccharomyces japonicus (Cdc8) and Saccharomyces cerevisiae (Tpm1 and Tpm2). We also describe a fluorescent probe to visualize mammalian tropomyosin (TPM2 isoform). Finally, we generated a camelid nanobody against S. pombe Cdc8, which mimics the localization of mNG-Cdc8 in vivo. Using these tools, we report the presence of tropomyosin in previously unappreciated patch-like structures in fission and budding yeasts, show flow of tropomyosin (F-actin) cables to the cytokinetic actomyosin ring and identify rearrangements of the actin cytoskeleton during mating. These powerful tools and strategies will aid better analyses of tropomyosin and F-actin cables in vivo., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)