title: Cdk1-dependent control of membrane-trafficking dynamics.
abstract: Cyclin-dependent kinase 1 (Cdk1) is required for initiation and maintenance of polarized cell growth in budding yeast. Cdk1 activates Rho-family GTPases, which polarize the actin cytoskeleton for delivery of membrane to growth sites via the secretory pathway. Here we investigate whether Cdk1 plays additional roles in the initiation and maintenance of polarized cell growth. We find that inhibition of Cdk1 causes a cell surface growth defect that is as severe as that caused by actin depolymerization. However, unlike actin depolymerization, Cdk1 inhibition does not result in a massive accumulation of intracellular secretory vesicles or their cargoes. Analysis of post-Golgi vesicle dynamics after Cdk1 inhibition demonstrates that exocytic vesicles are rapidly mistargeted away from the growing bud, possibly to the endomembrane/vacuolar system. Inhibition of Cdk1 also causes defects in the organization of endocytic and exocytic zones at the site of growth. Cdk1 thus modulates membrane-trafficking dynamics, which is likely to play an important role in coordinating cell surface growth with cell cycle progression.
authors: European Institute of Chemistry and Biology, 33607 Pessac, France.
authors: Derek
authors: D
authors: McCusker
authors: Anne
authors: A
authors: Royou
authors: Christophe
authors: C
authors: Velours
authors: Douglas
authors: D
authors: Kellogg
mesh_terms: D008841:Actin Cytoskeleton; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002453:Cell Cycle; D049108:Cell Enlargement; D002462:Cell Membrane; D016764:Cell Polarity; D004705:Endocytosis; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D016203:CDC2 Protein Kinase; D020741:rho GTP-Binding Proteins