Raven J Peterson, Ryan C Reed, Colin R Zamecnik, Marwa A Sallam, Joel A Finbloom, Francisco J Martinez, Joshua M Levy, Aekkacha Moonwiriyakit, Tejal A Desai, Michael Koval
{"title":"Apical integrins as a switchable target to regulate the epithelial barrier.","authors":"Raven J Peterson, Ryan C Reed, Colin R Zamecnik, Marwa A Sallam, Joel A Finbloom, Francisco J Martinez, Joshua M Levy, Aekkacha Moonwiriyakit, Tejal A Desai, Michael Koval","doi":"10.1242/jcs.263580","DOIUrl":"10.1242/jcs.263580","url":null,"abstract":"<p><p>Tight junctions regulate epithelial barrier function and have been shown to be influenced by multiple classes of proteins. Apical integrins have been identified as potential regulators of epithelial barrier function; however, only indirect approaches have been used to measure integrin regulation of the epithelial barrier. Here, we used polymeric nanowires conjugated with anti-integrin β1 antibodies to specifically target apically localized integrins in either their closed or open conformation. Barrier regulation by apical integrins was found to be conformation specific. Nanowires targeting integrins in the closed conformation increased epithelial permeability and caused zonula occludens-1 (ZO-1, also known as TJP1) to change from a linear to a ruffled morphology. Claudin-2 and claudin-4 colocalized with ZO-1 and were also ruffled; however, claudin-1 and claudin-7 remained linear. Ruffling was dependent on myosin light chain kinases (MLCKs) and Rho kinases (ROCKs). Conversely, targeting integrins in the open conformation decreased epithelial permeability and made junctions more linearized. Anti-integrin β1 nanowires differentially affected actin and talin (analyzed using pan-talin antibodies), depending on whether they contained activating or inhibitory antibodies. Thus, apical integrins can act as a conformation-sensitive switch that regulates epithelial barrier function.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11795292/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648303","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}
Johanna Grinat, Noah P Shriever, Maria A Christophorou
{"title":"Fantastic proteins and where to find them - histones, in the nucleus and beyond.","authors":"Johanna Grinat, Noah P Shriever, Maria A Christophorou","doi":"10.1242/jcs.262071","DOIUrl":"10.1242/jcs.262071","url":null,"abstract":"<p><p>Animal genomes are packaged into chromatin, a highly dynamic macromolecular structure of DNA and histone proteins organised into nucleosomes. This accommodates packaging of lengthy genomic sequences within the physical confines of the nucleus while also enabling precise regulation of access to genetic information. However, histones existed before chromatin and have lesser-known functions beyond genome regulation. Most notably, histones are potent antimicrobial agents, and the release of chromatin to the extracellular space is a defence mechanism nearly as ancient and widespread as chromatin itself. Histone sequences have changed very little throughout evolution, suggesting the possibility that some of their 'non-canonical' functions are at play in parallel or in concert with their genome regulatory functions. In this Review, we take an evolutionary perspective of histone, nuclear chromatin and extracellular chromatin biology and describe the known extranuclear and extracellular functions of histones. We detail molecular mechanisms of chromatin release and extracellular chromatin sensing, and we discuss their roles in physiology and disease. Finally, we present evidence and give a perspective on the potential of extracellular histones to act as bioactive, cell modulatory factors.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"137 24","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11827605/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142864253","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}
Jordana B Freemantle, Mhairi C Towler, Emma R Hudson, Thomas Macartney, Monika Zwirek, David J K Liu, David A Pan, Sreenivasan Ponnambalam, D Grahame Hardie
{"title":"AMPK associates with and causes fragmentation of the Golgi by phosphorylating the guanine nucleotide exchange factor GBF1.","authors":"Jordana B Freemantle, Mhairi C Towler, Emma R Hudson, Thomas Macartney, Monika Zwirek, David J K Liu, David A Pan, Sreenivasan Ponnambalam, D Grahame Hardie","doi":"10.1242/jcs.262182","DOIUrl":"10.1242/jcs.262182","url":null,"abstract":"<p><p>AMP-activated protein kinase (AMPK) is an energy sensor that regulates cellular functions in response to changes in energy availability. However, whether AMPK activity is spatially regulated, and the implications for cell function, have been unclear. We now report that AMPK associates with the Golgi, and that its activation by two specific pharmacological activators leads to Golgi fragmentation similar to that caused by the antibiotic Golgicide A, an inhibitor of Golgi-specific Brefeldin A resistance factor-1 (GBF1), a guanine nucleotide exchange factor that targets ADP-ribosylation factor 1 (ARF1). Golgi fragmentation in response to AMPK activators is lost in cells carrying gene knockouts of AMPK-α subunits. AMPK has been previously reported to phosphorylate GBF1 at residue Thr1337, and its activation causes phosphorylation at that residue. Importantly, Golgi disassembly upon AMPK activation is blocked in cells expressing a non-phosphorylatable GBF1-T1337A mutant generated by gene editing. Furthermore, the trafficking of a plasma membrane-targeted protein through the Golgi complex is delayed by AMPK activation. Our findings provide a mechanism to link AMPK activation during cellular energy stress to downregulation of protein trafficking involving the Golgi.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11827860/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142687210","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}
Rafael Lucena, Akshi Jasani, Steph Anastasia, Douglas Kellogg, Maria Alcaide-Gavilan
{"title":"Casein kinase 1 controls components of a TORC2 signaling network in budding yeast.","authors":"Rafael Lucena, Akshi Jasani, Steph Anastasia, Douglas Kellogg, Maria Alcaide-Gavilan","doi":"10.1242/jcs.262036","DOIUrl":"10.1242/jcs.262036","url":null,"abstract":"<p><p>Tor kinases play diverse and essential roles in control of nutrient signaling and cell growth. These kinases are assembled into two multiprotein complexes known as TORC1 and TORC2. In budding yeast, TORC2 relays nutrient-dependent signals that strongly influence growth rate and cell size. However, the mechanisms that control TORC2 signaling are poorly understood. Activation of TORC2 requires Mss4, a phosphatidylinositol 4-phosphate 5-kinase that recruits and activates downstream targets of TORC2. Localization of Mss4 to the plasma membrane is thought to be controlled by phosphorylation, and previous work has suggested that yeast homologs of casein kinase 1, Yck1 and Yck2 (referred to here collectively as Yck1/2), Control phosphorylation of Mss4. Here, we generated a new analog-sensitive allele of YCK2 and used it to test whether Yck1/2 influence localization of Mss4 or signaling in the TORC2 network. We found that Yck1/2 strongly influence Mss4 phosphorylation and localization, as well as influencing regulation of multiple components of the TORC2 network. However, inhibition of Yck1/2 causes mild effects on the best-characterized signaling axis in the TORC2 pathway, suggesting that Yck1/2 might play a larger role in influencing less well-understood aspects of TORC2 signaling.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"137 24","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11795287/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142864249","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}
Safia Mahabub Sauty, Ashley Fisher, Andrew Dolson, Krassimir Yankulov
{"title":"Mutations in the DNA processivity factor POL30 predispose the FLO11 locus to epigenetic instability in S. cerevisiae.","authors":"Safia Mahabub Sauty, Ashley Fisher, Andrew Dolson, Krassimir Yankulov","doi":"10.1242/jcs.262006","DOIUrl":"10.1242/jcs.262006","url":null,"abstract":"<p><p>The FLO genes in Saccharomyces cerevisiae are repressed by heterochromatin formation, involving histone deacetylases, transcription factors and non-coding RNAs. Here, we report that mutations in the processivity factor POL30 (PCNA) that show transient derepression at the subtelomeres and the mating-type loci do not derepress FLO loci. However, deletions of the replisome stability factors RRM3 and TOF1 along with pol30 mutations induced flocculation phenotypes. The phenotypes correlated with increased expression of reporter proteins driven by the FLO11 promoter, the frequency of silent to active conversions of FLO11, and reduced expression of the regulatory long non-coding RNAs ICR1 and PWR1. Alterations in the local replication landscape of FLO11 indicate a link between defects in the fork protection complex and the stability of gene silencing. Analyses of these mutants at the subtelomeres and the HMLα locus showed a similar derepression phenotype and suggest transient instability of both active and silent states of FLO11. We conclude that RRM3 and TOF1 interact differentially with the pol30 mutations to promote transient derepression or complete epigenetic conversions of FLO11. We suggest that the interaction between POL30, RRM3 and TOF1 is essential to maintain epigenetic stability at the studied loci.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11827858/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142648317","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":"TXNDC15, an ER-localized thioredoxin-like transmembrane protein, contributes to ciliary transition zone integrity.","authors":"Shingo Yamazaki, Taiju Fujii, Shuhei Chiba, Hye-Won Shin, Kazuhisa Nakayama, Yohei Katoh","doi":"10.1242/jcs.262123","DOIUrl":"https://doi.org/10.1242/jcs.262123","url":null,"abstract":"<p><p>Primary cilia have specific proteins on their membrane to fulfill their sensory functions. Preservation of the specific protein composition of cilia relies on the barrier function of the transition zone (TZ) located at the ciliary base. Defects in cilia and the TZ cause ciliopathies, which have diverse clinical manifestations, including Meckel syndrome (MKS). Many of the proteins mutated in individuals with MKS are known to constitute the MKS module of the TZ. Although TXNDC15 (also known as MKS14) is a thioredoxin-related transmembrane protein that is localized mainly in the endoplasmic reticulum (ER) and is mutated in individuals with MKS, its role at the TZ or within cilia has not been characterized. Here, we show that TXNDC15-knockout cells have defects in MKS module assembly and in ciliary membrane protein localization. These defects in TXNDC15-knockout cells were not rescued by exogenous expression of any of the TXNDC15 constructs with MKS variations in the thioredoxin domain. Furthermore, TXNDC15 with mutations of two cysteine residues within the thioredoxin domain failed to rescue defects in TXNDC15-knockout cells, suggesting that TXNDC15 controls the TZ integrity from outside the TZ via its thioredoxin domain.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"137 24","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142828703","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}
Ana C Almeida, Helder Rocha, Maximilian W D Raas, Hanh Witte, Ralf J Sommer, Berend Snel, Geert J P L Kops, Reto Gassmann, Helder Maiato
{"title":"An evolutionary perspective on the relationship between kinetochore size and CENP-E dependence for chromosome alignment.","authors":"Ana C Almeida, Helder Rocha, Maximilian W D Raas, Hanh Witte, Ralf J Sommer, Berend Snel, Geert J P L Kops, Reto Gassmann, Helder Maiato","doi":"10.1242/jcs.263466","DOIUrl":"10.1242/jcs.263466","url":null,"abstract":"<p><p>Chromosome alignment during mitosis can occur as a consequence of bi-orientation or is assisted by the CENP-E (kinesin-7) motor at kinetochores. We previously found that Indian muntjac chromosomes with larger kinetochores bi-orient more efficiently and are biased to align in a CENP-E-independent manner, suggesting that CENP-E dependence for chromosome alignment negatively correlates with kinetochore size. Here, we used targeted phylogenetic profiling of CENP-E in monocentric (localized centromeres) and holocentric (centromeres spanning the entire chromosome length) clades to test this hypothesis at an evolutionary scale. We found that, despite being present in common ancestors, CENP-E was lost more frequently in taxa with holocentric chromosomes, such as Hemiptera and Nematoda. Functional experiments in two nematodes with holocentric chromosomes in which a CENP-E ortholog is absent (Caenorhabditis elegans) or present (Pristionchus pacificus) revealed that targeted expression of human CENP-E to C. elegans kinetochores partially rescued chromosome alignment defects associated with attenuated polar-ejection forces, whereas CENP-E inactivation in P. pacificus had no detrimental effects on mitosis and viability. These data showcase the dispensability of CENP-E for mitotic chromosome alignment in species with larger kinetochores.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"137 24","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11827601/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142854283","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":"Biphasic DNA damage and non-canonical replication stress response govern radiation-induced senescence in glioblastoma.","authors":"Atanu Ghorai, Bhawna Singh, Shilpee Dutt","doi":"10.1242/jcs.261844","DOIUrl":"10.1242/jcs.261844","url":null,"abstract":"<p><p>Therapy-induced senescence (TIS) in glioblastoma (GBM) residual disease and escape from TIS account for resistance and recurrence, but the mechanism of TIS manifestation remains obscure. Here, we demonstrate that replication stress (RS) is critical for the induction of TIS in residual cells by employing an in vitro GBM therapy-resistance cellular model. Interestingly, we found a 'biphasic' mode of DNA damage after radiation treatment and reveal that the second phase of DNA damage arises majorly in the S phase of residual cells due to RS. Mechanistically, we show that persistent phosphorylated ATR is a safeguard for radiation resilience, whereas the other canonical RS molecules remain unaltered during the second phase of DNA damage. Importantly, RS preceded the induction of senescence, and ATR inhibition resulted in TIS reduction, leading to apoptosis. Moreover, ATR inhibition sensitized PARP-1 inhibitor-induced enhanced TIS-mediated resistance, leading to cell death. Our study demonstrates the crucial role of RS in TIS induction and maintenance in GBM residual cells, and targeting ATR alone or in combination with a PARP-1 inhibitor will be an effective strategy to eliminate TIS for better treatment outcomes.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142681886","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":"How to reduce your lab's carbon footprint.","authors":"Julie Welburn","doi":"10.1242/jcs.263722","DOIUrl":"https://doi.org/10.1242/jcs.263722","url":null,"abstract":"","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":"137 24","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142828608","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":"Shear stress-stimulated AMPK couples endothelial cell mechanics, metabolism and vasodilation.","authors":"Nicholas M Cronin, Logan W Dawson, Kris A DeMali","doi":"10.1242/jcs.262232","DOIUrl":"10.1242/jcs.262232","url":null,"abstract":"<p><p>Endothelial cells respond to mechanical force by stimulating cellular signaling, but how these pathways are linked to elevations in cell metabolism and whether metabolism supports the mechanical response remains poorly understood. Here, we show that the application of force to endothelial cells stimulates VE-cadherin to activate liver kinase B1 (LKB1; also known as STK11) and AMP-activated protein kinase (AMPK), a master regulator of energy homeostasis. VE-cadherin-stimulated AMPK increases eNOS (also known as NOS3) activity and localization to the plasma membrane, reinforcement of the actin cytoskeleton and cadherin adhesion complex, and glucose uptake. We present evidence for the increase in metabolism being necessary to fortify the adhesion complex, actin cytoskeleton and cellular alignment. Together, these data extend the paradigm for how mechanotransduction and metabolism are linked to include a connection to vasodilation, thereby providing new insight into how diseases involving contractile, metabolic and vasodilatory disturbances arise.</p>","PeriodicalId":15227,"journal":{"name":"Journal of cell science","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11795286/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604105","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}