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

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

SUBMITTER: Choi SH 

PROVIDER: S-EPMC2726783 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature