{"title":"寡聚化和胞囊偶联是裂变酵母中spa2介导的极化生长聚焦的基础。","authors":"Liping Ren, Alaina H Willet, Kathleen L Gould","doi":"10.1242/jcs.264071","DOIUrl":null,"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":3.6000,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450465/pdf/","citationCount":"0","resultStr":"{\"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\":null,\"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\":3.6000,\"publicationDate\":\"2025-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12450465/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of cell science\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1242/jcs.264071\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/9/11 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"CELL BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of cell science","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1242/jcs.264071","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/11 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
Oligomerization and exocyst coupling underlie Spa2-mediated focusing of polarized growth in fission yeast.
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.