title: Sensing a bud in the yeast morphogenesis checkpoint: a role for Elm1.
abstract: Bud formation by Saccharomyces cerevisiae must be coordinated with the nuclear cycle to enable successful proliferation. Many environmental stresses temporarily disrupt bud formation, and in such circumstances, the morphogenesis checkpoint halts nuclear division until bud formation can resume. Bud emergence is essential for degradation of the mitotic inhibitor, Swe1. Swe1 is localized to the septin cytoskeleton at the bud neck by the Swe1-binding protein Hsl7. Neck localization of Swe1 is required for Swe1 degradation. Although septins form a ring at the presumptive bud site before bud emergence, Hsl7 is not recruited to the septins until after bud emergence, suggesting that septins and/or Hsl7 respond to a "bud sensor." Here we show that recruitment of Hsl7 to the septin ring depends on a combination of two septin-binding kinases: Hsl1 and Elm1. We elucidate which domains of these kinases are needed and show that artificial targeting of those domains suffices to recruit Hsl7 to septin rings even in unbudded cells. Moreover, recruitment of Elm1 is responsive to bud emergence. Our findings suggest that Elm1 plays a key role in sensing bud emergence.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710.
authors.forename: Hui
authors.initials: H
authors.lastname: Kang
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332.
authors.forename: Denis
authors.initials: D
authors.lastname: Tsygankov
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710 daniel.lew@duke.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Lew
mesh_terms: D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D000072417:Protein Domains; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011484:Protein-Arginine N-Methyltransferases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D058112:Septins / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D029701:Saccharomyces cerevisiae Proteins; D011484:Protein-Arginine N-Methyltransferases; C120666:HSL7 protein, S cerevisiae; D011494:Protein Kinases; C411302:ELM1 protein, S cerevisiae; C106494:HSL1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D018844:Cyclin-Dependent Kinases; D058112:Septins