Phosphorylation state defines discrete roles for monopolin in chromosome attachment and spindle elongation.
Authors
Choi, Sung HughPéli-Gulli, Marie-Pierre
Mcleod, Iain
Sarkeshik, Ali
Yates, John R. III
Simanis, Viesturs
McCollum, Dannel
UMass Chan Affiliations
Department of Molecular Genetics and MicrobiologyDocument Type
Journal ArticlePublication Date
2009-06-23Keywords
AnaphaseAnimals
CDC2 Protein Kinase
Cell Cycle Proteins
Chromosome Segregation
Chromosomes
Kinetochores
Metaphase
Mitotic Spindle Apparatus
Multiprotein Complexes
Phosphorylation
Protein Tyrosine Phosphatases
Recombinant Fusion Proteins
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins
Schizosaccharomyces
Schizosaccharomyces pombe Proteins
Transcription Factors
Microbiology
Molecular Genetics
Metadata
Show full item recordAbstract
BACKGROUND: It is unknown how oscillations in Cdk1 activity drive the dramatic changes in chromosome and spindle dynamics that occur at the metaphase/anaphase transition. RESULTS: We show that the Schizosaccharomyces pombe monopolin complex has distinct functions in metaphase and anaphase that are determined by the phosphorylation state of its Mde4 subunit. When Cdk1 activity is high in metaphase, Mde4 is hyperphosphorylated on Cdk1 phosphorylation sites and localizes to kinetochores. A nonphosphorylatable mutant of Mde4 does not localize to kinetochores, appears prematurely on the metaphase spindle, and interferes with spindle dynamics and chromosome segregation, illustrating the importance of Cdk1 phosphorylation in regulating metaphase monopolin activity. When Cdk1 activity drops in anaphase, dephosphorylation of Mde4 triggers monopolin localization to the mitotic spindle, where it promotes spindle elongation and integrity, coupling the late mitotic loss of Cdk1 activity to anaphase spindle dynamics. CONCLUSIONS: Together, these findings illustrate how the sequential phosphorylation and dephosphorylation of monopolin helps ensure the orderly execution of discrete steps in mitosis.Source
Curr Biol. 2009 Jun 23;19(12):985-95. Epub 2009 Jun 11.Permanent Link to this Item
http://hdl.handle.net/20.500.14038/37365PubMed ID
19523829Related Resources
Link to article in PubMedCollections
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