Journal
MOLECULAR BIOLOGY OF THE CELL
Volume 17, Issue 3, Pages 1065-1074Publisher
AMER SOC CELL BIOLOGY
DOI: 10.1091/mbc.E05-07-0640
Keywords
-
Categories
Funding
- NCRR NIH HHS [P41 RR-01823, P41 RR011823] Funding Source: Medline
- NIGMS NIH HHS [T32 GM-07270, R01 GM040506, R01 GM-40506, T32 GM007270] Funding Source: Medline
Ask authors/readers for more resources
The Saccharomyces cerevisiae inhibitor of apoptosis (IAP) repeat protein Bir1 localizes as a chromosomal passenger. A deletion analysis of Bir1 identified two regions important for function. The C-terminal region is essential for growth, binds Sli15, and is necessary and sufficient for the localization of Bir1 as a chromosomal passenger. The middle region is not essential but is required to localize the inner kinetochore protein Ndc10 to the spindle during anaphase and to the midzone at telophase. In contrast, precise deletion of the highly conserved IAP repeats conferred no phenotype and did not alter the cell cycle delay caused by loss of cohesin. Bir1 is phosphorylated in a cell cycle-dependent manner. Mutation of all nine CDK consensus sites in the middle region of Bir1 significantly decreased the level of phosphorylation and blocked localization of Ndc10 to the spindle at anaphase. Moreover, immunoprecipitation of Ndc10 with Bir1 was dependent on phosphorylation. The loss of Ndc10 from the anaphase spindle prevented elongation of the spindle beyond 7 mu m. We conclude that phosphorylation of the middle region of Bir1 is required to bring Ndc10 to the spindle at anaphase, which is required for full spindle elongation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available