N-terminal regions of Mps1 kinase determine functional bifurcation.
Mps1 is a conserved kinase that in budding yeast functions in duplication of the spindle pole body (SPB), spindle checkpoint activation, and kinetochore biorientation. The identity of Mps1 targets and the subdomains that convey specificity remain largely unexplored. Using a novel combination of systematic deletion analysis and chemical biology, we identified two regions within the N terminus of Mps1 that are essential for either SPB duplication or kinetochore biorientation. Suppression analysis of the MPS1 mutants defective in SPB duplication and biochemical enrichment of Mps1 identified the essential SPB components Spc29 and the yeast centrin Cdc31 as Mps1 targets in SPB duplication. Our data suggest that phosphorylation of Spc29 by Mps1 in G1/S recruits the Mps2-Bbp1 complex to the newly formed SPB to facilitate its insertion into the nuclear envelope. Mps1 phosphorylation of Cdc31 at the conserved T110 residue controls substrate binding to Kar1 protein. These findings explain the multiple SPB duplication defects of mps1 mutants on a molecular level.
Araki
Yasuhiro
Y
Zentrum für Molekulare Biologie der Universität Heidelberg, Deutsches Krebsforschungszentrum-ZMBH Allianz, 69120 Heidelberg, Germany.
Gombos
Linda
L
Migueleti
Suellen P S
SP
Sivashanmugam
Lavanya
L
Antony
Claude
C
Schiebel
Elmar
E
D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism; D008868:Microtubule Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism
C404863:BBP1 protein, S cerevisiae; C083769:CDC31 protein, S cerevisiae; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; C505600:Spc29 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C093416:MPS1 protein, S cerevisiae