Novel functional dissection of the localization-specific roles of budding yeast polo kinase Cdc5p.
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.
Park
Jung-Eun
JE
Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Park
Chong J
CJ
Sakchaisri
Krisada
K
Karpova
Tatiana
T
Asano
Satoshi
S
McNally
James
J
Sunwoo
Yangil
Y
Leem
Sun-Hee
SH
Lee
Kyung S
KS
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D048749:Cytokinesis; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D008938:Mitosis; D009154:Mutation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology
D018797:Cell Cycle Proteins; C432934:Cnm67 protein, S cerevisiae; D003598:Cytoskeletal Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C099685:SWE1 protein, S cerevisiae; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C081927:CDC5 protein, S cerevisiae