Overexpression of the yeast MCK1 protein kinase suppresses conditional mutations in centromere-binding protein genes CBF2 and CBF5.
We find that overexpression in yeast of the yeast MCK1 gene, which encodes a meiosis and centromere regulatory kinase, suppresses the temperature-sensitive phenotype of certain mutations in essential centromere binding protein genes CBF2 and CBF5. Since Mck1p is a known serine/threonine protein kinase, this suppression is postulated to be due to Mck1p-catalyzed in vivo phosphorylation of centromere binding proteins. Evidence in support of this model was provided by the finding that purified Mck1p phosphorylates in vitro the 110 kDa subunit (Cbf2p) of the multimeric centromere binding factor CBF3. This phosphorylation occurs on both serine and threonine residues in Cbf2p.
Department of Biology, University of California, Santa Barbara 93106.
W
W
Jiang
M Y
MY
Lim
H J
HJ
Yoon
J
J
Thorner
G S
GS
Martin
J
J
Carbon
D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D018628:Gene Dosage; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000235:genetics; D038362:Glycogen Synthase Kinase 3; D006836:Hydro-Lyases; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012694:Serine / Q000378:metabolism; D013489:Suppression, Genetic / Q000235:genetics*; D013696:Temperature; D013912:Threonine / Q000378:metabolism
C071249:CBP2 protein, S cerevisiae; D005656:Fungal Proteins; D008869:Microtubule-Associated Proteins; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D013912:Threonine; D012694:Serine; D011505:Protein-Tyrosine Kinases; D038362:Glycogen Synthase Kinase 3; C068124:MCK1 protein, S cerevisiae; D006836:Hydro-Lyases; C082278:CBF5 protein, S cerevisiae