{"title":"Cell volume regulates terminal differentiation of cultured human epidermal keratinocytes.","authors":"Sebastiaan Zijl, Toru Hiratsuka, Atefeh Mobasseri, Mirsana Ebrahimkutty, Mandy Börmel, Sergi Garcia-Manyes, Fiona M Watt","doi":"10.1242/jcs.264242","DOIUrl":"10.1242/jcs.264242","url":null,"abstract":"<p><p>To gain insights into the human epidermal stem cell niche, we have previously identified micron-scale topographical substrates that regulate differentiation of spread keratinocytes. On one substrate (S1), cells interact with circular topographies and differentiation is stimulated; on the other (S2), cells interact with triangular topographies and differentiation is inhibited. Cell stiffness on S1 and S2 was similar, and nuclear localisation of the mechano-sensitive transcriptional regulator YAP1 was decreased on S1 and S2 compared to on flat substrates. However, cells on S2 exhibited reduced cell volume, leading us to explore the potential for volume-regulated differentiation. Treatment with polyethylene glycol decreased cell volume and inhibited differentiation under a range of conditions. Conversely, deionized water increased cell volume and stimulated differentiation. Bulk RNA sequencing identified several substrate-responsive genes, including aquaporins and ion channels. A membrane permeable Ca2+ chelator and an inhibitor of the water channel aquaporin 3 blocked volume-induced differentiation. These studies identify cell volume as a mechanism by which keratinocyte-niche interactions regulate terminal differentiation.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450470/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144731133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"APEX2-based quantitative proteomics of LAT and CD3ζ interactomes in living human Jurkat T cells unveils new interactors.","authors":"Juan-José Saez, Michaël Richard, Vivien Caillens, Stéphanie Dogniaux, Federico Marconi, Florent Dingli, Damarys Loew, Hermine Ferran, Loredana Saveanu, Claire Hivroz, Laurence Bataille","doi":"10.1242/jcs.263981","DOIUrl":"10.1242/jcs.263981","url":null,"abstract":"<p><p>T cell receptor (TCR) stimulation induces a signaling cascade that starts with the phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) present in the TCR-CD3 complex. This is followed by the phosphorylation of proteins including LAT, which once phosphorylated interacts with multiple proteins allowing signal diversification and amplification. We take advantage of APEX2-based peroxidase-catalyzed proximity labeling combined with quantitative mass spectrometry to track the formation and dynamics of CD3ζ (also known as CD247) and LAT interactomes in TCR-activated Jurkat T cells. We identify, with high confidence, more than 1000 proteins for each bait, and we provide a quantitative molecular map of proteins that are enriched or depleted in the vicinity of CD3ζ and LAT after TCR stimulation. We detail and compare the recruitment kinetics of signaling proteins to CD3ζ and LAT, and identify uncharacterized mediators of T cell activation. We show that the kinase MARK2, which is in the proximity of LAT and CD3ζ at resting state and lost upon activation, is a negative regulator of cytokine production by T cells. This study provides a resource for uncovering the complex signaling networks that regulate TCR activation and highlights new players involved in this signaling cascade.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144690403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quantification of cyclin-CDK dissociation constants using FCCS with green and near-infrared fluorescent proteins.","authors":"Aika Toyama, Yuhei Goto, Yuhei Yamauchi, Hironori Sugiyama, Yohei Kondo, Atsushi Mochizuki, Kazuhiro Aoki","doi":"10.1242/jcs.263921","DOIUrl":"10.1242/jcs.263921","url":null,"abstract":"<p><p>The cell cycle is a highly coordinated process governed by cyclin-bound cyclin-dependent kinases (CDKs). Although the interactions between cyclins and CDKs are well documented, the dissociation constants (Kd) for specific cyclin-CDK pairs within living cells remain poorly understood. Fluorescence cross-correlation spectroscopy (FCCS) enables quantification of the Kd, but challenges remain in selecting an optimal pair of fluorescent molecules for FCCS in a living cell. In this study, we demonstrate that mNeonGreen and phycocyanobilin-bound miRFP670 represent a suitable pair for FCCS in living cells from the viewpoint of high photostability and low bleedthrough. This fluorescent protein pair enables us to measure the Kd values of the CDK Cdc2 and B-type cyclin Cdc13 in fission yeast cells. Moreover, we roughly estimated the Kd values for 36 cyclin-CDK complexes formed by nine distinct cyclins and four CDKs in mammalian cells, including unconventional cyclin-CDK pairs. These measurements suggest potential versatility of cyclin-CDK binding in cell cycle progression, with implications for understanding cell cycle regulation in both fission yeast and higher eukaryotes.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144753491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Basement membranes at a glance.","authors":"Rachel Lennon, David R Sherwood","doi":"10.1242/jcs.263947","DOIUrl":"10.1242/jcs.263947","url":null,"abstract":"<p><p>Basement membranes (BMs) underlie or surround most tissues. They are formed of secreted proteins that associate with cell surfaces and are the most ancient animal extracellular matrix. Laminin and collagen IV are core components that polymerize into self-associating networks, providing BMs with an organizing scaffold and tensile strength. In humans, BMs also contain over 150 other secreted proteins, such as structural matrix components, enzymes and growth factors, as well as over 50 cell-membrane adhesion and signalling receptors. From this toolbox, BMs are tailored for tissue-specific functions, including filtration, shaping organs, connecting tissues and harbouring signals that guide cell migration and differentiation. Highlighting their importance to human health, defects in genes encoding BM proteins are associated with over 100 disease phenotypes. Advancing our understanding of BM regulation, function and dysregulation will reveal new approaches to prevent many human disorders and preserve tissue health. Here, we review our current understanding of BM composition, formation and function, and outline how BMs change with ageing and disease.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"138 17","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450471/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Oligomerization and exocyst coupling underlie Spa2-mediated focusing of polarized growth in fission yeast.","authors":"Liping Ren, Alaina H Willet, Kathleen L Gould","doi":"10.1242/jcs.264071","DOIUrl":"10.1242/jcs.264071","url":null,"abstract":"<p><p>Polarized cell growth in fungi requires the spatial restriction of exocytosis to discrete cortical domains. Defined by a characteristic domain architecture, the evolutionarily conserved scaffold protein Spa2 localizes to sites of polarized growth in fungi and has been implicated in morphogenic processes including hyphal extension in filamentous fungi and budding yeast mating. Schizosaccharomyces pombe is a well-studied and powerful model organism for elucidating mechanisms of polarized growth. However, identifying a role for Spa2 in S. pombe morphogenesis has been elusive, highlighting a gap in defining a broadly conserved Spa2 function. Here, we undertook a comprehensive and comparative dissection of the targeting mechanisms, interactome and function of Spa2 in S. pombe. We find that all of the conserved domains in Spa2 influence Spa2 localization to sites of polarized growth in an exocyst-dependent and largely cytoskeleton-independent manner. At cell tips, stable complexes of oligomerized Spa2 contribute to constraining the growth zone, in part by delivering the Rab GTPase-activating protein for the Sec4 homolog Ypt2. Despite species-specific wiring of Spa2 protein networks, our results underscore an evolutionarily conserved role for Spa2 in sharpening the spatial focus of polarized growth.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"138 17","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450465/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145033504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jorel R Padilla, Yunshu Qiu, Gretchen Kimmel, Grace Aleck, Lillie Ferreira, Sharon Wu, William Gibbons, Torrey R Mandigo, Eric S Folker
{"title":"Dystrophin interacts with Msp300 to regulate myonuclear positioning and microtubule organization.","authors":"Jorel R Padilla, Yunshu Qiu, Gretchen Kimmel, Grace Aleck, Lillie Ferreira, Sharon Wu, William Gibbons, Torrey R Mandigo, Eric S Folker","doi":"10.1242/jcs.263712","DOIUrl":"10.1242/jcs.263712","url":null,"abstract":"<p><p>In Drosophila myogenesis, myonuclei are actively moved during embryogenesis, and their spacing is maintained through an anchoring mechanism in the fully differentiated myofiber. Although we have identified microtubule-associated proteins, motors and nuclear envelope proteins that regulate myonuclear spacing, the developmental time during which each gene functions has not been tested. Here, we identify Dystrophin as being required only for the maintenance of myonuclear spacing. Furthermore, we demonstrate that Dystrophin genetically interacts with Msp300, a gene encoding a KASH-domain protein, to maintain myonuclear spacing. Mechanistically, both Dystrophin and Msp300 regulate microtubule organization. Specifically, in animals with disrupted expression of both Dystrophin and Msp300, microtubule colocalization with thin filaments is reduced. Taken together, these data indicate that the peripheral membrane protein Dystrophin and the outer nuclear membrane protein Msp300 together regulate the organization of the microtubule network, which then acts as an anchor to restrict myonuclear movement in contractile myofibers. These data are consistent with growing evidence that myonuclear movement and myonuclear spacing are crucial to muscle development, muscle function and muscle repair, and provide a mechanism to connect disparate muscle diseases.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144816751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alessia Del Chiaro, Nenad Grujic, Jierui Zhao, Ranjith Kumar Papareddy, Peng Gao, Juncai Ma, Christian Lofke, Anuradha Bhattacharya, Ramona Gruetzner, Pierre Bourguet, Frédéric Berger, Byung-Ho Kang, Sylvestre Marillonnet, Yasin Dagdas
{"title":"An A. thaliana mutant lacking all nine ATG8 isoforms provides genetic evidence for functional specialization of ATG8 in plants.","authors":"Alessia Del Chiaro, Nenad Grujic, Jierui Zhao, Ranjith Kumar Papareddy, Peng Gao, Juncai Ma, Christian Lofke, Anuradha Bhattacharya, Ramona Gruetzner, Pierre Bourguet, Frédéric Berger, Byung-Ho Kang, Sylvestre Marillonnet, Yasin Dagdas","doi":"10.1242/jcs.263803","DOIUrl":"10.1242/jcs.263803","url":null,"abstract":"<p><p>Autophagy sustains cellular health by recycling damaged or excess components through autophagosomes. Autophagy is mediated by conserved ATG proteins, among which the ubiquitin-like ATG8 proteins play a central role by linking cargo to the growing autophagosomes. Unlike most ATG proteins, the ATG8 gene family is significantly expanded in vascular plants, but its functional specialization remains poorly understood. Using transcriptional and translational reporters in Arabidopsis thaliana, we revealed that ATG8 isoforms are differentially expressed across tissues and form distinct autophagosomes. To explore ATG8 specialization, we generated the nonuple Δatg8 mutant, lacking all nine ATG8 isoforms. The mutant displayed hypersensitivity to carbon and nitrogen starvation, coupled with defects in bulk and selective autophagy, as shown by biochemical and ultrastructural analyses. Complementation experiments demonstrated that ATG8A could rescue both carbon and nitrogen starvation phenotypes, whereas ATG8H could only complement carbon starvation. Proximity labeling proteomics further identified isoform-specific interactors under nitrogen starvation, underscoring their functional divergence. These findings provide genetic evidence for functional specialization of ATG8 isoforms in plants and lay the foundation for investigating their roles in diverse cell types and stress conditions.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450472/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144855326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rishika Abrol, Syeda Farhana Afroz, James E B Curson, Karoline D Raven, Kaustav Das Gupta, Kimberley S Gunther, Alun Jones, Robert C Reid, Zherui Xiong, Jennifer H Gunter, Jessica A Engel, Christian R Engwerda, Antje Blumenthal, David P Fairlie, Robert G Parton, Steven Zuryn, Ronan Kapetanovic, Divya Ramnath, Matthew J Sweet
{"title":"Histone deacetylase 7 mediates lipopolysaccharide-inducible mitochondrial fission in macrophages.","authors":"Rishika Abrol, Syeda Farhana Afroz, James E B Curson, Karoline D Raven, Kaustav Das Gupta, Kimberley S Gunther, Alun Jones, Robert C Reid, Zherui Xiong, Jennifer H Gunter, Jessica A Engel, Christian R Engwerda, Antje Blumenthal, David P Fairlie, Robert G Parton, Steven Zuryn, Ronan Kapetanovic, Divya Ramnath, Matthew J Sweet","doi":"10.1242/jcs.264376","DOIUrl":"https://doi.org/10.1242/jcs.264376","url":null,"abstract":"<p><p>Histone deacetylase 7 (HDAC7) drives several immunometabolism-related processes in macrophages including lipopolysaccharide (LPS)-inducible glycolysis and inflammatory mediator production. Using an advanced biotin ligase TurboID system in human macrophages, we report 104 candidate HDAC7 interaction partners that may contribute to its immunometabolic functions. One such protein is the mitochondrial fission-promoting GTPase dynamin-related protein 1 (DRP1), which associates with HDAC7 in cells. Using gain- and loss-of-function genetic approaches, we show that HDAC7 promotes LPS-inducible mitochondrial fission in macrophages, as well as DRP1-dependent metabolic and inflammatory responses. HDAC7 enzymatic activity was dispensable for LPS-inducible fission, as previously reported for LPS-inducible glycolysis. However, a pharmacological inhibitor of HDAC7 attenuated fission in primary human and mouse macrophages, implicating its acetyl-lysine docking function in this response. HDAC7 thus drives inducible mitochondrial fission in macrophages. Small molecules targeting the acetyl-lysine docking function of HDAC7 may have applications in preventing pathological processes driven by dysregulated mitochondrial fission.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shu Yao Leong, Laura Muras, Benedikt S J Fischer, Sehee Jang, Anastasia Gurskaya, Mayank Chugh, Serapion Pyrpassopoulos, Hauke Drechsler, Erik Schäffer
{"title":"The plant kinesin-12 POK2 tail is a versatile interaction hub.","authors":"Shu Yao Leong, Laura Muras, Benedikt S J Fischer, Sehee Jang, Anastasia Gurskaya, Mayank Chugh, Serapion Pyrpassopoulos, Hauke Drechsler, Erik Schäffer","doi":"10.1242/jcs.263785","DOIUrl":"https://doi.org/10.1242/jcs.263785","url":null,"abstract":"<p><p>Tissue development and function rely on correct cell patterning. In plants, patterns are determined by the new cell wall formed during mitosis. Already in preprophase, ring-like, positional cues mark the future division plane on the plasma membrane in embryophytes. These cues include the kinesin-12 motors PHRAGMOPLAST ORIENTING KINESIN 2 (POK2) and its paralogue POK1. They are essential for correctly aligning the phragmoplast - a microtubule scaffold for cell wall formation. Although we have a basic understanding of how these motors align the phragmoplast, we currently lack information on how they are targeted and maintained at the plasma membrane. Here, we reconstituted recombinant POK2 tail fragments on microtubules and vesicles in vitro. We found that the POK2 tail interacted with microtubules, the microtubule-associated protein MAP65-3, as well as with certain anionic lipids. We identified a short element in the POK2 tail responsible for all three interactions. Our data suggest a sequential and cooperative mechanism that targets POK2 specifically to the future division site. There, it is robustly maintained through interactions with the plasma membrane to establish the cell division plane.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tatsat Banerjee, Yu Deng, Dhiman Sankar Pal, Huiwang Zhan, Pablo A Iglesias, Peter N Devreotes
{"title":"Signaling and actin waves at a glance.","authors":"Tatsat Banerjee, Yu Deng, Dhiman Sankar Pal, Huiwang Zhan, Pablo A Iglesias, Peter N Devreotes","doi":"10.1242/jcs.263634","DOIUrl":"10.1242/jcs.263634","url":null,"abstract":"<p><p>Waves of signaling and cytoskeletal components, which can be easily seen propagating on the ventral surface of a cell, are a systemic feature of biochemical networks that define the spatiotemporal dynamics of diverse cell physiological processes. In this Cell Science at a Glance article and the accompanying poster, we summarize the origin, mathematical basis, and function of signaling and actin waves from systems biology and biophysics perspectives, focusing on cell migration and polarity. We describe how waves control membrane protrusion morphologies, how different proteins and lipids are organized within the waves by distinct mechanisms, and how excitable network-based mathematical models can explain wave patterns and predict cell behavior. We further delineate how specific components interact biochemically to generate these dynamic patterns. Finally, we provide a set of generalizable underlying biophysical principles to describe the exquisite subcellular organization of signaling and cytoskeletal events, membrane symmetry breaking, protein compartmentalization and wave propagation.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"138 16","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12380181/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}