Cytoskeleton最新文献_第6页

IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-26 DOI: 10.1002/cm.21868

引用次数: 0

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IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-26 DOI: 10.1002/cm.21869

引用次数: 0

Prediction of the essential intermolecular contacts for side-binding of VASP on F-actin 预测 VASP 在 F-actin 上侧结合所必需的分子间接触点

IF 2.4 4区生物学

Cytoskeleton Pub Date : 2024-04-22 DOI: 10.1002/cm.21864

Fikret Aydin, Harshwardhan H. Katkar, Alisha Morganthaler, Alyssa J. Harker, David R. Kovar, Gregory A. Voth

{"title":"Prediction of the essential intermolecular contacts for side-binding of VASP on F-actin","authors":"Fikret Aydin, Harshwardhan H. Katkar, Alisha Morganthaler, Alyssa J. Harker, David R. Kovar, Gregory A. Voth","doi":"10.1002/cm.21864","DOIUrl":"10.1002/cm.21864","url":null,"abstract":"Vasodilator-stimulated phosphoprotein (VASP) family proteins play a crucial role in mediating the actin network architecture in the cytoskeleton. The Ena/VASP homology 2 (EVH2) domain in each of the four identical arms of the tetrameric VASP consists of a loading poly-Pro region, a G-actin-binding domain (GAB), and an F-actin-binding domain (FAB). Together, the poly-Pro, GAB, and FAB domains allow VASP to bind to sides of actin filaments in a bundle, and recruit profilin–G-actin to processively elongate the filaments. The atomic resolution structure of the ternary complex, consisting of the loading poly-Pro region and GAB domain of VASP with profilin–actin, has been solved over a decade ago; however, a detailed structure of the FAB-F-actin complex has not been resolved to date. Experimental insights, based on homology of the FAB domain with the C region of WASP, have been used to hypothesize that the FAB domain binds to the cleft between subdomains 1 and 3 of F-actin. Here, in order to develop our understanding of the VASP–actin complex, we first augment known structural information about the GAB domain binding to actin with the missing FAB domain-actin structure, which we predict using homology modeling and docking simulations. In earlier work, we used mutagenesis and kinetic modeling to study the role of domain-level binding–unbinding kinetics of Ena/VASP on actin filaments in a bundle, specifically on the side of actin filaments. We further look at the nature of the side-binding of the FAB domain of VASP at the atomistic level using our predicted structure, and tabulate effective mutation sites on the FAB domain that would disrupt the VASP–actin complex. We test the binding affinity of Ena with mutated FAB domain using total internal reflection fluorescence microscopy experiments. The binding affinity of VASP is affected significantly for the mutant, providing additional support for our predicted structure.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 8","pages":"382-392"},"PeriodicalIF":2.4,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cm.21864","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140637007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Girishkumar Kumaran, PhD 吉里什库马尔-库马兰，博士

IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-18 DOI: 10.1002/cm.21862

Girishkumar Kumaran

引用次数: 0

Probing actin-activated ATP turnover kinetics of human cardiac myosin II by single molecule fluorescence 通过单分子荧光探测人心肌肌球蛋白 II 的肌动蛋白激活 ATP 转化动力学

IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-16 DOI: 10.1002/cm.21858

Albin Berg, Lok Priya Velayuthan, Sven Tågerud, Marko Ušaj, Alf Månsson

{"title":"Probing actin-activated ATP turnover kinetics of human cardiac myosin II by single molecule fluorescence","authors":"Albin Berg, Lok Priya Velayuthan, Sven Tågerud, Marko Ušaj, Alf Månsson","doi":"10.1002/cm.21858","DOIUrl":"https://doi.org/10.1002/cm.21858","url":null,"abstract":"Mechanistic insights into myosin II energy transduction in striated muscle in health and disease would benefit from functional studies of a wide range of point-mutants. This approach is, however, hampered by the slow turnaround of myosin II expression that usually relies on adenoviruses for gene transfer. A recently developed virus-free method is more time effective but would yield too small amounts of myosin for standard biochemical analyses. However, if the fluorescent adenosine triphosphate (ATP) and single molecule (sm) total internal reflection fluorescence microscopy previously used to analyze basal ATP turnover by myosin alone, can be expanded to actin-activated ATP turnover, it would appreciably reduce the required amount of myosin. To that end, we here describe zero-length cross-linking of human cardiac myosin II motor fragments (sub-fragment 1 long [S1L]) to surface-immobilized actin filaments in a configuration with maintained actin-activated ATP turnover. After optimizing the analysis of sm fluorescence events, we show that the amount of myosin produced from C2C12 cells in one 60 mm cell culture plate is sufficient to obtain both the basal myosin ATP turnover rate and the maximum actin-activated rate constant (kcat). Our analysis of many single binding events of fluorescent ATP to many S1L motor fragments revealed processes reflecting basal and actin-activated ATPase, but also a third exponential process consistent with non-specific ATP-binding outside the active site.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"292 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Haplo-insufficiency of Profilin1 in vascular endothelial cells is beneficial but not sufficient to confer protection against experimentally induced atherosclerosis 血管内皮细胞中 Profilin1 的单倍体缺陷有益于防止实验诱导的动脉粥样硬化，但还不足以起到保护作用

IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-16 DOI: 10.1002/cm.21859

Abigail Allen-Gondringer, David Gau, Partha Dutta, Partha Roy

{"title":"Haplo-insufficiency of Profilin1 in vascular endothelial cells is beneficial but not sufficient to confer protection against experimentally induced atherosclerosis","authors":"Abigail Allen-Gondringer, David Gau, Partha Dutta, Partha Roy","doi":"10.1002/cm.21859","DOIUrl":"https://doi.org/10.1002/cm.21859","url":null,"abstract":"Actin cytoskeleton plays an important role in various aspects of atherosclerosis, a key driver of ischemic heart disease. Actin-binding protein Profilin1 (Pfn1) is overexpressed in atherosclerotic plaques in human disease, and Pfn1, when partially depleted globally in all cell types, confers atheroprotection in vivo. This study investigates the impact of endothelial cell (EC)-specific partial loss of Pfn1 expression in atherosclerosis development. We utilized mice engineered for conditional heterozygous knockout of the Pfn1 gene in ECs, with atherosclerosis induced by depletion of hepatic LDL receptor by gene delivery of PCSK9 combined with high-cholesterol diet. Our studies show that partial depletion of EC Pfn1 has certain beneficial effects marked by dampening of select pro-atherogenic cytokines (CXCL10 and IL7) with concomitant reduction in cytotoxic T cell abundance but is not sufficient to reduce hyperlipidemia and confer atheroprotection in vivo. In light of these findings, we conclude that atheroprotective phenotype conferred by global Pfn1 haplo-insufficiency requires contributions of additional cell types that are relevant for atherosclerosis progression.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"49 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Post‐translational modifications of vertebrate striated muscle myosin heavy chains 脊椎动物横纹肌肌球蛋白重链的翻译后修饰

IF 2.9 4区生物学

Cytoskeleton Pub Date : 2024-04-08 DOI: 10.1002/cm.21857

Paula Nieto Morales, Arianna N. Coons, Amelia J. Koopman, Sonu Patel, P. Bryant Chase, Michelle S. Parvatiyar, Jose R. Pinto

{"title":"Post‐translational modifications of vertebrate striated muscle myosin heavy chains","authors":"Paula Nieto Morales, Arianna N. Coons, Amelia J. Koopman, Sonu Patel, P. Bryant Chase, Michelle S. Parvatiyar, Jose R. Pinto","doi":"10.1002/cm.21857","DOIUrl":"https://doi.org/10.1002/cm.21857","url":null,"abstract":"Post‐translational modifications (PTMs) play a crucial role in regulating the function of many sarcomeric proteins, including myosin. Myosins comprise a family of motor proteins that play fundamental roles in cell motility in general and muscle contraction in particular. A myosin molecule consists of two myosin heavy chains (MyHCs) and two pairs of myosin light chains (MLCs); two MLCs are associated with the neck region of each MyHC's N‐terminal head domain, while the two MyHC C‐terminal tails form a coiled‐coil that polymerizes with other MyHCs to form the thick filament backbone. Myosin undergoes extensive PTMs, and dysregulation of these PTMs may lead to abnormal muscle function and contribute to the development of myopathies and cardiovascular disorders. Recent studies have uncovered the significance of PTMs in regulating MyHC function and showed how these PTMs may provide additional modulation of contractile processes. Here, we discuss MyHC PTMs that have been biochemically and/or functionally studied in mammals' and rodents' striated muscle. We have identified hotspots or specific regions in three isoforms of myosin (MYH2, MYH6, and MYH7) where the prevalence of PTMs is more frequent and could potentially play a significant role in fine‐tuning the activity of these proteins.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"51 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical relationships between axoneme distortion and internal forces and torques in ciliary beating 纤毛跳动时轴丝变形与内力和扭矩之间的理论关系

IF 2.4 4区生物学

Cytoskeleton Pub Date : 2024-03-28 DOI: 10.1002/cm.21856

Louis G. Woodhams, Philip V. Bayly

{"title":"Theoretical relationships between axoneme distortion and internal forces and torques in ciliary beating","authors":"Louis G. Woodhams, Philip V. Bayly","doi":"10.1002/cm.21856","DOIUrl":"10.1002/cm.21856","url":null,"abstract":"The axoneme is an intricate nanomachine responsible for generating the propulsive oscillations of cilia and flagella in an astonishing variety of organisms. New imaging techniques based on cryoelectron-tomography (cryo-ET) and subtomogram averaging have revealed the detailed structures of the axoneme and its components with sub-nm resolution, but the mechanical function of each component and how the assembly generates oscillations remains stubbornly unclear. Most explanations of oscillatory behavior rely on the dynamic regulation of dynein by some signal, but this may not be necessary if the system of dynein-driven slender filaments is dynamically unstable. Understanding the possibility of instability-driven oscillations requires a multifilament model of the axoneme that accounts for distortions of the axoneme as it bends. Active bending requires forces and bending moments that will tend to change the spacing and alignment of doublets. We hypothesize that components of the axoneme resist and respond to these loads in ways that are critical to beating. Specifically, we propose (i) that radial spokes provide torsional stiffness by resisting misalignment (as well as spacing) between the central pair and outer doublets, and (ii) that the kinematics of dynein arms affect the relationships between active forces and bending moments on deforming doublets. These proposed relationships enhance the ability of theoretical, multifilament models of axonemal beating to generate propulsive oscillatory waveforms via dynamic mechanical instability.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 11","pages":"605-617"},"PeriodicalIF":2.4,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140308161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sarcomeric tropomyosin expression during human iPSC differentiation into cardiomyocytes 在人类 iPSC 分化为心肌细胞的过程中肉瘤肌球蛋白的表达。

IF 2.4 4区生物学

Cytoskeleton Pub Date : 2024-03-12 DOI: 10.1002/cm.21850

Dipak K. Dube, Syamalima Dube, Huaiyu Shi, Patricia Benz, Samender Randhawa, Yingli Fan, Jusuo Wang, Zhen Ma, Joseph W. Sanger, Jean M. Sanger, Bernard J. Poiesz

{"title":"Sarcomeric tropomyosin expression during human iPSC differentiation into cardiomyocytes","authors":"Dipak K. Dube, Syamalima Dube, Huaiyu Shi, Patricia Benz, Samender Randhawa, Yingli Fan, Jusuo Wang, Zhen Ma, Joseph W. Sanger, Jean M. Sanger, Bernard J. Poiesz","doi":"10.1002/cm.21850","DOIUrl":"10.1002/cm.21850","url":null,"abstract":"Tropomyosin (TPM) is an essential sarcomeric component, stabilizing the thin filament and facilitating actin's interaction with myosin. In mammals, including humans, there are four TPM genes (TPM1, TPM2, TPM3, and TPM4) each of which generates a multitude of TPM isoforms via alternative splicing and using different promoters. In this study, we have examined the expression of transcripts as well as proteins of various sarcomeric TPM isoforms during human inducible pluripotent stem cell differentiation into cardiomyocytes. During the differentiation time course, we harvested cells on Days 0, 5, 10, 15, and 20 to analyze for various sarcomeric TPM transcripts by qRT-PCR and for sarcomeric TPM proteins using two-dimensional Western blot with sarcomeric TPM-specific CH1 monoclonal antibody followed by mass spectra analyses. Our results show increasing levels of total TPM transcripts and proteins during the period of differentiation, but varying levels of specific TPM isoforms during the same period. By Day 20, the rank order of TPM transcripts was TPM1α > TPM1κ > TPM2α > TPM1μ > TPM3α > TPM4α. TPM1α was the dominant protein produced with some TPM2 and much less TPM1κ and μ. Interestingly, small amounts of two lower molecular weight TPM3 isoforms were detected on Day 15. To the best of our knowledge this is the first demonstration of TPM1μ non-muscle isoform protein expression before and during cardiac differentiation.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 9-10","pages":"448-472"},"PeriodicalIF":2.4,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140102957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distribution and bulk flow analyses of the intraflagellar transport (IFT) motor kinesin-2 support an “on-demand” model for Chlamydomonas ciliary length control 对鞭毛内运输（IFT）马达驱动蛋白-2的分布和散流分析支持衣藻纤毛长度控制的 "按需 "模型。

IF 2.4 4区生物学

Cytoskeleton Pub Date : 2024-03-08 DOI: 10.1002/cm.21851

Mansi B. Patel, Paul J. Griffin, Spencer F. Olson, Jin Dai, Yuqing Hou, Tara Malik, Poulomi Das, Gui Zhang, Winston Zhao, George B. Witman, Karl F. Lechtreck

{"title":"Distribution and bulk flow analyses of the intraflagellar transport (IFT) motor kinesin-2 support an “on-demand” model for Chlamydomonas ciliary length control","authors":"Mansi B. Patel, Paul J. Griffin, Spencer F. Olson, Jin Dai, Yuqing Hou, Tara Malik, Poulomi Das, Gui Zhang, Winston Zhao, George B. Witman, Karl F. Lechtreck","doi":"10.1002/cm.21851","DOIUrl":"10.1002/cm.21851","url":null,"abstract":"Most cells tightly control the length of their cilia. The regulation likely involves intraflagellar transport (IFT), a bidirectional motility of multi-subunit particles organized into trains that deliver building blocks into the organelle. In Chlamydomonas, the anterograde IFT motor kinesin-2 consists of the motor subunits FLA8 and FLA10 and the nonmotor subunit KAP. KAP dissociates from IFT at the ciliary tip and diffuses back to the cell body. This observation led to the diffusion-as-a-ruler model of ciliary length control, which postulates that KAP is progressively sequestered into elongating cilia because its return to the cell body will require increasingly more time, limiting motor availability at the ciliary base, train assembly, building block supply, and ciliary growth. Here, we show that Chlamydomonas FLA8 also returns to the cell body by diffusion. However, more than 95% of KAP and FLA8 are present in the cell body and, at a given time, just ~1% of the motor participates in IFT. After repeated photobleaching of both cilia, IFT of fluorescent kinesin subunits continued indicating that kinesin-2 cycles from the large cell-body pool through the cilia and back. Furthermore, growing and full-length cilia contained similar amounts of kinesin-2 subunits and the size of the motor pool at the base changed only slightly with ciliary length. These observations are incompatible with the diffusion-as-a-ruler model, but rather support an “on-demand model,” in which the cargo load of the trains is regulated to assemble cilia of the desired length.","PeriodicalId":55186,"journal":{"name":"Cytoskeleton","volume":"81 11","pages":"586-604"},"PeriodicalIF":2.4,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11380706/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140061396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0