Robinson L C, Hubbard E J, Graves P R, DePaoli-Roach A A, Roach P J, Kung C, Haas D W, Hagedorn C H, Goebl M, Culbertson M R
University of Wisconsin, Madison 53706.
Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):28-32. doi: 10.1073/pnas.89.1.28.
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.
我们报告了一对编码蛋白激酶同源物的酿酒酵母必需基因的分离。这两个基因作为剂量依赖性抑制子被独立分离出来。YCK1剂量增加可抑制因SNF1蛋白激酶活性降低而导致的缺陷，YCK2剂量增加可缓解野生型细胞对盐胁迫的敏感性。在两种生长测定中，这两个基因功能相同，单独缺失任一基因的功能对生长没有明显影响。然而，两个基因功能均缺失会导致细胞无法存活。两个预测的蛋白质产物总体氨基酸同一性为77%，并含有蛋白激酶中保守的序列元件。兔酪蛋白激酶I的部分序列与这两个酵母基因产物的同一性为64%。此外，在过表达YCK2的细胞提取物中观察到酪蛋白激酶I活性增加。因此，YCK1和YCK2似乎编码酪蛋白激酶I同源物。
