Yeast casein kinase I homologues: an essential gene pair.
We report the isolation of an essential pair of Saccharomyces cerevisiae genes that encode protein kinase homologues. The two genes were independently isolated as dosage-dependent suppressors. Increased dosage of YCK1 suppressed defects caused by reduced SNF1 protein kinase activity, and increased dosage of YCK2 relieved sensitivity of wild-type cells to salt stress. The two genes function identically in the two growth assays, and loss of function of either gene alone has no discernible effect on growth. However, loss of function of both genes results in inviability. The two predicted protein products share 77% overall amino acid identity and contain sequence elements conserved among protein kinases. Partial sequence obtained for rabbit casein kinase I shares 64% identity with the two yeast gene products. Moreover, an increase in casein kinase I activity is observed in extracts from cells overexpressing YCK2. Thus YCK1 and YCK2 appear to encode casein kinase I homologues.
Robinson
L C
LC
University of Wisconsin, Madison 53706.
Hubbard
E J
EJ
Graves
P R
PR
DePaoli-Roach
A A
AA
Roach
P J
PJ
Kung
C
C
Haas
D W
DW
Hagedorn
C H
CH
Goebl
M
M
Culbertson
M R
MR
D000595:Amino Acid Sequence; D047389:Casein Kinase I; D047388:Casein Kinases; D003001:Cloning, Molecular; D015870:Gene Expression; D005800:Genes, Fungal; D016153:Genes, Suppressor; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D011494:Protein Kinases / Q000235:genetics* / Q000502:physiology; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment
D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D047389:Casein Kinase I; D047388:Casein Kinases; C479664:YCK1 protein, S cerevisiae; C479666:YCK2 protein, S cerevisiae