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Title

Phosphorylation state defines discrete roles for monopolin in chromosome attachment and spindle elongation.

Authors

Sung Hugh Choi, University of Massachusetts Medical SchoolFollow
Marie-Pierre Péli-Gulli, EPFL SV ISREC UPSIM
Iain Mcleod, Scripps Research Institute
Ali Sarkeshik, Scripps Research Institute
John R. Yates III, Scripps Research Institute
Viesturs Simanis, Scripps Research Institute
Dannel McCollum, University of Massachusetts Medical SchoolFollow

UMMS Affiliation

Department of Molecular Genetics and Microbiology

Publication Date

6-23-2009

Document Type

Article

Subjects

Anaphase; Animals; 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

Disciplines

Microbiology | Molecular Genetics

Abstract

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.

Journal/Book/Conference Title

Current biology : CB

Related Resources

Link to article in PubMed

PubMed ID

19523829

Repository Citation

Choi, Sung Hugh; Péli-Gulli, Marie-Pierre; Mcleod, Iain; Sarkeshik, Ali; Yates, John R. III; Simanis, Viesturs; and McCollum, Dannel, "Phosphorylation state defines discrete roles for monopolin in chromosome attachment and spindle elongation." (2009). Molecular Genetics and Microbiology Publications and Presentations. 29.
https://escholarship.umassmed.edu/mgm_pp/29