The Saccharomyces cerevisiae YAK1 gene encodes a protein kinase that is induced by arrest early in the cell cycle.
Null mutations in the gene YAK1, which encodes a protein with sequence homology to known protein kinases, suppress the cell cycle arrest phenotype of mutants lacking the cyclic AMP-dependent protein kinase (A kinase). That is, loss of the YAK1 protein specifically compensates for loss of the A kinase. Here, we show that the protein encoded by YAK1 has protein kinase activity. Yak1 kinase activity is low during exponential growth but is induced at least 50-fold by arrest of cells prior to the completion of S phase. Induction is not observed by arrest at stages later in the cell cycle. Depending on the arrest regimen, induction can occur either by an increase in Yak1 protein levels or by an increase in Yak1 specific activity. Finally, an increase in Yak1 protein levels causes growth arrest of cells with attenuated A kinase activity. These results suggest that Yak1 acts in a pathway parallel to that of the A kinase to negatively regulate cell proliferation.
Garrett
S
S
Section of Cell Growth, Regulation and Oncogenesis, Duke University Medical Center, Durham, North Carolina 27710.
Menold
M M
MM
Broach
J R
JR
D001483:Base Sequence; D002453:Cell Cycle; D004790:Enzyme Induction; D005800:Genes, Fungal; D005838:Genotype; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010641:Phenotype; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins
D047908:Intracellular Signaling Peptides and Proteins; D015345:Oligonucleotide Probes; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C062391:YAK1 protein, S cerevisiae