The Yak1 protein kinase of Saccharomyces cerevisiae moderates thermotolerance and inhibits growth by an Sch9 protein kinase-independent mechanism.
The growth defect associated with the loss of yeast A kinase activity can be alleviated by the overexpression or deletion of two other kinases, Sch9 and Yak1, respectively. Using tests of epistasis, we have shown that Sch9 and Yak1 define separate signaling pathways and must, therefore, suppress the A kinase defect by different mechanisms. Nevertheless, the Yak1 kinase appears to regulate cellular processes that are under A kinase control. For example, acquisition of heat resistance is correlated with Yak1 kinase activity, such that YAK1-overexpressing cells are over 200-fold more resistant than isogenic yak1 strains. These results, for the first time, associate a phenotype, other than suppression of the A kinase growth defect, with the loss of Yak1 activity and argue a broader role for the Yak1 kinase in cell growth.
Hartley
A D
AD
Section of Cell Growth, Duke University Medical Center, Durham, North Carolina 27710.
Ward
M P
MP
Garrett
S
S
D002453:Cell Cycle; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D005690:Galactose / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D006358:Hot Temperature; D047908:Intracellular Signaling Peptides and Proteins; D016296:Mutagenesis; D010641:Phenotype; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion
D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C071569:SCH9 protein kinase; D017346:Protein Serine-Threonine Kinases; C062391:YAK1 protein, S cerevisiae; D017868:Cyclic AMP-Dependent Protein Kinases; D005690:Galactose