Novel functional dissection of the localization-specific roles of budding yeast polo kinase Cdc5p

Mol Cell Biol. 2004 Nov;24(22):9873-86. doi: 10.1128/MCB.24.22.9873-9886.2004.

Abstract

Budding yeast polo kinase Cdc5p localizes to the spindle pole body (SPB) and to the bud-neck and plays multiple roles during M-phase progression. To dissect localization-specific mitotic functions of Cdc5p, we tethered a localization-defective N-terminal kinase domain of Cdc5p (Cdc5pDeltaC) to the SPB or to the bud-neck with components specifically localizing to one of these sites and characterized these mutants in a cdc5Delta background. Characterization of a viable, SPB-localizing, CDC5DeltaC-CNM67 mutant revealed that it is defective in timely degradation of Swe1p, a negative regulator of Cdc28p. Loss of BFA1, a negative regulator of mitotic exit, rescued the lethality of a neck-localizing CDC5DeltaC-CDC12 or CDC5DeltaC-CDC3 mutant but yielded severe defects in cytokinesis. These data suggest that the SPB-associated Cdc5p activity is critical for both mitotic exit and cytokinesis, whereas the bud neck-localized Cdc5p is required for proper Swe1p regulation. Interestingly, a cdc5Delta bfa1Delta swe1Delta triple mutant is viable but grows slowly, whereas cdc5Delta cells bearing both CDC5DeltaC-CNM67 and CDC5DeltaC-CDC12 grow well with only a mild cell cycle delay. Thus, SPB- and the bud-neck-localized Cdc5p control most of the critical Cdc5p functions and downregulation of Bfa1p and Swe1p at the respective locations are two critical factors that require Cdc5p.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Division
  • Cytokinesis
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Genes, Fungal
  • Mitosis
  • Mutation
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Serine-Threonine Kinases
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Spindle Apparatus / metabolism
  • Subcellular Fractions / enzymology

Substances

  • Cell Cycle Proteins
  • Cnm67 protein, S cerevisiae
  • Cytoskeletal Proteins
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Protein Kinases
  • SWE1 protein, S cerevisiae
  • Protein-Tyrosine Kinases
  • Protein Serine-Threonine Kinases
  • CDC5 protein, S cerevisiae