Budding yeast centrosome duplication requires stabilization of Spc29 via Mps1-mediated phosphorylation.
Protein phosphorylation plays an important role in the regulation of centrosome duplication. In budding yeast, numerous lines of evidence suggest a requirement for multiple phosphorylation events on individual components of the centrosome to ensure their proper assembly and function. Here, we report the first example of a single phosphorylation event on a component of the yeast centrosome, or spindle pole body (SPB), that is required for SPB duplication and cell viability. This phosphorylation event is on the essential SPB component Spc29 at a conserved Thr residue, Thr(240). Mutation of Thr(240) to Ala is lethal at normal gene dosage, but an increased copy number of this mutant allele results in a conditional phenotype. Phosphorylation of Thr(240) was found to promote the stability of the protein in vivo and is catalyzed in vitro by the Mps1 kinase. Furthermore, the stability of newly synthesized Spc29 is reduced in a mutant strain with reduced Mps1 kinase activity. These results demonstrate the first evidence for a single phosphorylation event on an SPB component that is absolutely required for SPB duplication and suggest that the Mps1 kinase is responsible for this protein-stabilizing phosphorylation.
Holinger
Eric P
EP
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309-0347, USA.
Old
William M
WM
Giddings
Thomas H
TH
Wong
Catherine
C
Yates
John R
JR
Winey
Mark
M
D002453:Cell Cycle; D002470:Cell Survival; D018385:Centrosome / Q000502:physiology*; D019084:Fluorescent Antibody Technique, Indirect; D015151:Immunoblotting; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D008941:Spindle Apparatus
D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; C505600:Spc29 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C093416:MPS1 protein, S cerevisiae