The COMA complex is required for Sli15/INCENP-mediated correction of defective kinetochore attachments.
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.
Knockleby
James
J
Department of Biology, McGill University, Montreal, QC, Canada.
Vogel
Jackie
J
D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D018386:Kinetochores / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
C509718:Ame1 protein, S cerevisiae; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D008869:Microtubule-Associated Proteins; C509719:Okp1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C480084:Sli15 protein, S cerevisiae