Chemical genetics reveals a role for Mps1 kinase in kinetochore attachment during mitosis.
Accurate chromosome segregation depends on proper assembly and function of the kinetochore and the mitotic spindle. In the budding yeast, Saccharomyces cerevisiae, the highly conserved protein kinase Mps1 has well-characterized roles in spindle pole body (SPB, yeast centrosome equivalent) duplication and the mitotic checkpoint. However, an additional role for Mps1 is suggested by phenotypes of MPS1 mutations that include genetic interactions with kinetochore mutations and meiotic chromosome segregation defects and also by the localization of Mps1 at the kinetochore, the latter being independent of checkpoint activation. We have developed a new MPS1 allele, mps1-as1, that renders the kinase specifically sensitive to a cell-permeable ATP analog inhibitor, allowing us to perform high-resolution execution point experiments that identify a novel role for Mps1 subsequent to SPB duplication. We demonstrate, by using both fixed- and live-cell fluoresence techniques, that cells lacking Mps1 function show severe defects in mitotic spindle formation, sister kinetochore positioning at metaphase, and chromosome segregation during anaphase. Taken together, our experiments are consistent with an important role for Mps1 at the kinetochore in mitotic spindle assembly and function.
Jones
Michele H
MH
Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80309-0347, USA.
Huneycutt
Brenda J
BJ
Pearson
Chad G
CG
Zhang
Chao
C
Morgan
Garry
G
Shokat
Kevan
K
Bloom
Kerry
K
Winey
Mark
M
D000595:Amino Acid Sequence; D015153:Blotting, Western; D017489:CDC28 Protein Kinase, S cerevisiae / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D018386:Kinetochores / Q000378:metabolism* / Q000502:physiology; D008854:Microscopy, Electron; D008938:Mitosis / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D008941:Spindle Apparatus / Q000378:metabolism*
D029701:Saccharomyces cerevisiae Proteins; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017489:CDC28 Protein Kinase, S cerevisiae; C093416:MPS1 protein, S cerevisiae