|Phospho-Regulation of Kinetochore-Microtubule Attachments by the Aurora Kinase Ipl1p.|
Cheeseman IM, Anderson S, Jwa M, Green EM, Kang J-S, Yates III JR, Chan CSM, Drubin DG, Barnes G
Category: cytoskeleton ¤ Added: Oct 22, 2002 ¤ Rating: ◊◊
The Aurora kinase Ipl1p plays a crucial role in regulating kinetochore-microtubule attachments in budding yeast, but the underlying basis for this regulation is not known. To identify Ipl1p targets, we first purified 28 kinetochore proteins from yeast protein extracts. These studies identified five previously uncharacter- ized kinetochore proteins and defined two additional kinetochore subcomplexes. We then used mass spec- trometry to identify 18 phosphorylation sites in 7 of these 28 proteins. Ten of these phosphorylation sites are targeted directly by Ipl1p, allowing us to identify a consensus phosphorylation site for an Aurora kinase. Our systematic mutational analysis of the Ipl1p phosphorylation sites demonstrated that the essential mi- crotubule binding protein Dam1p is a key Ipl1p target for regulating kinetochore-microtubule attachments in vivo.