title: Coordination of chromatid separation and spindle elongation by antagonistic activities of mitotic and S-phase CDKs.
abstract: Because cohesion prevents sister-chromatid separation and spindle elongation, cohesion dissolution may trigger these two events simultaneously. However, the relatively normal spindle elongation kinetics in yeast cohesin mutants indicates an additional mechanism for the temporal control of spindle elongation. Here we show evidence indicating that S-phase CDK (cyclin dependent kinase) negatively regulates spindle elongation. In contrast, mitotic CDK promotes spindle elongation by activating Cdc14 phosphatase, which reverses the protein phosphorylation imposed by S-phase CDK. Our data suggest that S-phase CDK negatively regulates spindle elongation partly through its phosphorylation of a spindle pole body (SPB) protein Spc110. We also show that hyperactive S-phase CDK compromises the microtubule localization of Stu2, a processive microtubule polymerase essential for spindle elongation. Strikingly, we found that hyperactive mitotic CDK induces uncoupled spindle elongation and sister-chromatid separation in securin mutants (pds1Δ), and we speculate that asynchronous chromosome segregation in pds1Δ cells contributes to this phenotype. Therefore, the tight temporal control of spindle elongation and cohesin cleavage assure orchestrated chromosome separation and spindle elongation.
authors.affiliation: Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, USA.
authors.forename: Fengshan
authors.initials: F
authors.lastname: Liang
authors.forename: Daniel
authors.initials: D
authors.lastname: Richmond
authors.forename: Yanchang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002842:Chromatids / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation / Q000235:genetics; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000235:genetics / Q000648:ultrastructure; D008938:Mitosis / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D016196:S Phase / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D064249:Securin; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D000097722:Cohesins
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D017027:Protein Tyrosine Phosphatases; D029701:Saccharomyces cerevisiae Proteins; D064249:Securin; D000097722:Cohesins; C074860:CDC14 protein, S cerevisiae; C578004:PDS1 protein, S cerevisiae; C109414:STU2 protein, S cerevisiae