The COMA complex is required for Sli15/INCENP-mediated correction of defective kinetochore attachments

Cell Cycle. 2009 Aug 15;8(16):2570-7. doi: 10.4161/cc.8.16.9267. Epub 2009 Aug 12.

Abstract

Before anaphase, kinetochores of sister chromatid (SC) pairs must be attached to microtubules emanating from opposing spindle poles. The conserved Aurora B kinase Ipl1 and its adaptor INCENP/Sli15 correct defective attachments and promote SC bi-orientation. Ame1 and Okp1 are essential components of the COMA sub-complex of the budding yeast central kinetochore, and Ame1 has been demonstrated to physically interact with Sli15. Here, we examine the significance of the Ame1-Sli15 interaction in vivo. We find Sli15 localization at kinetochores is reduced in the absence of Ame1. We demonstrate a role for Ame1 in the correction of defective attachments. While overexpression of OKP1 restores kinetochore localization of the mutant Ame1-4 protein, Sli15 localization is not restored and defective attachments are not corrected. Our findings reveal a new role for the central kinetochore in promoting Sli15 function, and suggest functional Ame1 is required for the correction of defective attachments by promoting the localization of Sli15/INCENP at kinetochores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle / genetics
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Immunoblotting
  • Kinetochores / metabolism*
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • Ame1 protein, S cerevisiae
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Microtubule-Associated Proteins
  • Okp1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sli15 protein, S cerevisiae