Cytoskeleton (Hoboken, N.J.)最新文献

{"title":"Tubules, Rods, and Spirals: Diverse Modes of SepF-FtsZ Assembling.","authors":"Jagrity Choudhury, Barnali N Chaudhuri","doi":"10.1002/cm.21975","DOIUrl":"https://doi.org/10.1002/cm.21975","url":null,"abstract":"<p><p>Z-ring formation by FtsZ, the master assembler of the divisome, is a key step in bacterial cell division. Membrane anchoring of the Z-ring requires the assistance of dedicated Z-ring binding proteins, such as SepF and FtsA. SepF participates in bundling and membrane anchoring of FtsZ in gram-positive bacteria. We report in vitro biophysical studies of the interactions between FtsZ and a cytoplasmic component of cognate SepF from three different bacteria: Mycobacterium tuberculosis, Staphylococcus aureus, and Enterococcus gallinarum. While the cytosolic domain of SepF from M. tuberculosis is primarily a dimer, those from S. aureus and E. gallinarum polymerize to form ring-like structures. Mycobacterial SepF helps in the bundling of FtsZ filaments to form thick filaments and large spirals. On the other hand, ring-forming SepF from the Firmicutes bundle FtsZ into tubules. Our results suggest that the oligomeric form of SepF directs how it bundles FtsZ filaments.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142866740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overexpressed Palladin Rescues Enteropathogenic E. coli (EPEC) Pedestal Lengths in ArpC2 Depleted Cells.","authors":"Kaitlin M Bruzzini, S Tara Mann, Julian A Guttman","doi":"10.1002/cm.21974","DOIUrl":"https://doi.org/10.1002/cm.21974","url":null,"abstract":"<p><p>Enteropathogenic Escherichia coli (EPEC) causes diarrheal disease. Once ingested, these extracellular pathogens attach to the intestinal epithelial cells of their host, collapse the localized microvilli, and generate actin-rich structures within the host cells that are located beneath the attached bacteria, called \"pedestals.\" Palladin is an actin-associated protein that cross-links and stabilizes actin filaments. This protein also acts as a scaffolding protein for other actin-binding proteins. Here, we examine the role of Palladin during EPEC infections and show that Palladin is co-opted by EPEC. Depletion of Palladin resulted in shorter pedestals, and when Palladin containing mutations in either its actin- or VASP-binding domains were overexpressed in cells, pedestals decreased in length. Importantly, we show that the overexpression of Palladin in ArpC2^-/- (Arp2/3 complex-depleted) cells rescued pedestal length. Together, our results demonstrate that Palladin has the ability to rescue pedestal length during EPEC infections when the function of the Arp2/3 complex is diminished.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conformational Regulation of Vertebrate γ-Tubulin Ring Complexes by CM1 Proteins.","authors":"Michal Wieczorek","doi":"10.1002/cm.21979","DOIUrl":"https://doi.org/10.1002/cm.21979","url":null,"abstract":"","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Author Profile: Kyle Paul Smith.","authors":"Kyle P Smith","doi":"10.1002/cm.21973","DOIUrl":"https://doi.org/10.1002/cm.21973","url":null,"abstract":"","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142848156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FAK and p130Cas Modulate Stiffness-Mediated Early Transcription and Cellular Metabolism.","authors":"Bat-Ider Tumenbayar, Khanh Pham, John C Biber, Vincent M Tutino, Joseph A Brazzo, Peng Yao, Yongho Bae","doi":"10.1002/cm.21971","DOIUrl":"10.1002/cm.21971","url":null,"abstract":"<p><p>Cellular metabolism is influenced by the stiffness of the extracellular matrix. Focal adhesion kinase (FAK) and its binding partner, p130Cas, transmit biomechanical signals, such as substrate stiffness, to the cell to regulate a variety of cellular responses, but their roles in early transcriptional and metabolic responses remain largely unexplored. We cultured mouse embryonic fibroblasts with or without siRNA-mediated FAK or p130Cas knockdown and assessed the early transcriptional responses of these cells to placement on soft and stiff substrates by RNA sequencing and bioinformatics analyses. Exposure to the stiff substrate altered the expression of genes important for metabolic and biosynthetic processes, and these responses were influenced by knockdown of FAK and p130Cas. Our findings reveal that FAK-p130Cas signaling mechanotransduces substrate stiffness to early transcriptional changes that alter cellular metabolism and biosynthesis.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142803724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteocyte Dendrites: How Do They Grow, Mature, and Degenerate in Mineralized Bone?","authors":"Rosa M Guerra, Velia M Fowler, Liyun Wang","doi":"10.1002/cm.21964","DOIUrl":"https://doi.org/10.1002/cm.21964","url":null,"abstract":"<p><p>Osteocytes, the most abundant bone cells, form an extensive cellular network via interconnecting dendrites. Like neurons in the brain, the long-lived osteocytes perceive mechanical and biological inputs and signal to other effector cells, leading to the homeostasis and turnover of bone tissues. Despite the appreciation of osteocytes' vital roles in bone biology, the initiation, growth, maintenance, and eventual degradation of osteocyte dendrites are poorly understood due to their full encasement by mineralized matrix. With the advancement of imaging modalities and genetic models, the architectural organization and molecular composition of the osteocyte dendrites, as well as their morphological changes with aging and diseases, have begun to be revealed. However, several long-standing mysteries remain unsolved, including (1) how the dendrites are initiated and elongated when a surface osteoblast becomes embedded as an osteocyte; (2) how the dendrites maintain a relatively stable morphology during their decades-long life span; (3) what biological processes control the dendrite morphology, connectivity, and stability; and (4) if these processes are influenced by age, sex, hormones, and mechanical loading. Our review of long, thin actin filament (F-actin)-containing processes extending from other cells leads to a working model that serves as a starting point to investigate the formation and maintenance of osteocyte dendrites and their degradation with aging and diseases.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142803765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unjamming Transition as a Paradigm for Biomechanical Control of Cancer Metastasis.","authors":"Grace Cai, Nicole C Rodgers, Allen P Liu","doi":"10.1002/cm.21963","DOIUrl":"https://doi.org/10.1002/cm.21963","url":null,"abstract":"<p><p>Tumor metastasis is a complex phenomenon that poses significant challenges to current cancer therapeutics. While the biochemical signaling involved in promoting motile phenotypes is well understood, the role of biomechanical interactions has recently begun to be incorporated into models of tumor cell migration. Specifically, we propose the unjamming transition, adapted from physical paradigms describing the behavior of granular materials, to better discern the transition toward an invasive phenotype. In this review, we introduce the jamming transition broadly and narrow our discussion to the different modes of 3D tumor cell migration that arise. Then we discuss the mechanical interactions between tumor cells and their neighbors, along with the interactions between tumor cells and the surrounding extracellular matrix. We center our discussion on the interactions that induce a motile state or unjamming transition in these contexts. By considering the interplay between biochemical and biomechanical signaling in tumor cell migration, we can advance our understanding of biomechanical control in cancer metastasis.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142781931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Actin Polymerization Status Regulates Tenocyte Homeostasis Through Myocardin-Related Transcription Factor-A.","authors":"Valerie C West, Kaelyn E Owen, Kameron L Inguito, Karl Matthew M Ebron, Tori N Reiner, Chloe E Mirack, Christian H Le, Rita de Cassia Marqueti, Steven Snipes, Rouhollah Mousavizadeh, Rylee E King, Dawn M Elliott, Justin Parreno","doi":"10.1002/cm.21962","DOIUrl":"10.1002/cm.21962","url":null,"abstract":"<p><p>The actin cytoskeleton is a potent regulator of tenocyte homeostasis. However, the mechanisms by which actin regulates tendon homeostasis are not entirely known. This study examined the regulation of tenocyte molecule expression by actin polymerization via the globular (G-) actin-binding transcription factor, myocardin-related transcription factor-a (MRTF). We determined that decreasing the proportion of G-actin in tenocytes by treatment with TGFβ1 increases nuclear MRTF. These alterations in actin polymerization and MRTF localization coincided with favorable alterations to tenocyte gene expression. In contrast, latrunculin A increases the proportion of G-actin in tenocytes and reduces nuclear MRTF, causing cells to acquire a tendinosis-like phenotype. To parse out the effects of F-actin depolymerization from regulation by MRTF, we treated tenocytes with cytochalasin D. Exposure of cells to cytochalasin D increases the proportion of G-actin in tenocytes. However, as compared to latrunculin A, cytochalasin D has a differential effect on MRTF localization by increasing nuclear MRTF. This led to an opposing effect on the regulation of a subset of genes. The differential regulation of genes by latrunculin A and cytochalasin D suggests that actin signals through MRTF to regulate a specific subset of genes. By targeting the deactivation of MRTF through the inhibitor CCG1423, we verify that MRTF regulates Type I Collagen, Tenascin C, Scleraxis, and α-smooth muscle actin in tenocytes. Actin polymerization status is a potent regulator of tenocyte homeostasis through the modulation of several downstream pathways, including MRTF. Understanding the regulation of tenocyte homeostasis by actin may lead to new therapeutic interventions against tendinopathies, such as tendinosis.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Actin Isovariant ACT2-Mediated Cellular Auxin Homeostasis Regulates Lateral Root Organogenesis in Arabidopsis thaliana.","authors":"Aya Hanzawa, Arifa Ahamed Rahman, Abidur Rahman","doi":"10.1002/cm.21956","DOIUrl":"https://doi.org/10.1002/cm.21956","url":null,"abstract":"<p><p>Lateral root (LR) organogenesis is regulated by cellular flux of auxin within pericycle cells, which depends on the membrane distribution and polar localization of auxin carrier proteins. The correct distribution of auxin carrier proteins relies on the intracellular trafficking of these proteins aided by filamentous actin as a track. However, the precise role of actin in lateral root development is still elusive. Here, using vegetative class actin isovariant mutants, we revealed that loss of actin isovariant ACT8 led to increased lateral root formation. The distribution of auxin within pericycle cells was altered in act8 mutant, primarily due to the altered distribution of AUX1 and PIN7. Interestingly, incorporation of act2 mutant in act8 background (act2act8) effectively nullified the LR phenotype observed in act8 mutant, indicating that ACT2 plays an important role in LR development. To explore further, we investigated the possibility that the act8 mutant's LR phenotype and cellular auxin distribution resulted from ACT2 overexpression. Consistent with the idea, enhanced lateral root formation, altered AUX1, PIN7 expression, and auxin distribution in pericycle cells were observed in ACT2 overexpression lines. Collectively, these results suggest that actin isovariant ACT2 but not ACT8 plays a pivotal role in regulating source-to-sink auxin distribution during lateral root organogenesis.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyses of Off-Target Effects on Cardiac and Skeletal Muscles by Berberine, a Drug Used to Treat Cancers and Induce Weight Loss.","authors":"Jushuo Wang, Yingli Fan, Syamalima Dube, Patricia Benz, Dipak Dube, Jean M Sanger, Joseph W Sanger","doi":"10.1002/cm.21950","DOIUrl":"https://doi.org/10.1002/cm.21950","url":null,"abstract":"<p><p>Previous reports from our laboratory describing the formation of myofibrils in cultured embryonic cardiac and skeletal muscle cells have proposed that myofibrillogenesis occurs in three steps of increasing protein organization: beginning with premyofibrils, followed by nascent myofibrils, and ending in mature myofibrils. Inhibitors of the ubiquitin proteasome system (UPS) prevented nascent myofibrils from progressing directly to mature myofibrils in cultured cardiac and skeletal muscle cells, supporting a three-step model of assembly in which some of the proteins in nascent myofibrils are proteolyzed to allow the assembly of mature myofibrils. Application of UPS inhibitors on cultured muscle cells suggests possible explanations for the off-target cardiac and skeletal muscle adverse effects of UPS drugs, which are used on cancer patients. Berberine, a plant derivative, has been used to treat various cancers, including multiple myelomas. In contrast to the use of UPS drugs, success was reported with Berberine in multiple myeloma patients with no off-target effects on their hearts. We have exposed cultured cardiac and skeletal muscle cells to Berberine, a ligase inhibitor of UHRF1 (ubiquitin-like with PHD and RING finger domains). Berberine inhibited myofibril assembly at the nascent myofibril stage in embryonic skeletal muscle cells but had no effect in the assembly of mature myofibrils in embryonic heart cells. RT-PCR experiments demonstrated Berberine inhibition of mRNA for muscle myosin II heavy chains but not for muscle actin mRNA in skeletal muscle cells. Berberine is also being used as a popular weight losing compound, because it is much cheaper and available without a prescription than the semaglutide containing weight losing drugs (Wegovy and Ozempic). In contrast to Berberine, semaglutide had no effects on myofibril assembly in culture assays for both cardiac and skeletal muscle cells. We postulate that analyses of cultured embryonic cardiac and skeletal muscle cells will provide a preclinical assay for the testing of novel cancer drugs with improved outcomes for patients, an important goal for cancer therapeutics.</p>","PeriodicalId":72766,"journal":{"name":"Cytoskeleton (Hoboken, N.J.)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142633794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}