TESTIS-SPECIFIC MAK PROTEIN-KINASE IS EXPRESSED SPECIFICALLY IN THE MEIOTIC PHASE IN SPERMATOGENESIS AND IS ASSOCIATED WITH A 210-KILODALTON CELLULAR PHOSPHOPROTEIN

被引:56
作者
JINNO, A
TANAKA, K
MATSUSHIME, H
HANEJI, T
SHIBUYA, M
机构
[1] UNIV TOKYO, INST MED SCI, DEPT GENET, MINATO KU, TOKYO 108, JAPAN
[2] CHIBA UNIV, SCH MED, DEPT ANAT, CHUO KU, CHIBA 260, JAPAN
关键词
D O I
10.1128/MCB.13.7.4146
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The mak gene encodes a new protein kinase distantly related to cdc2 kinase, and its transcripts are expressed exclusively in testicular germ cells at and after meiosis (H. Matsushime, A. Jinno, N. Takagi, and M. Shibuya, Mol. Cell. Biol. 10:2261-2268, 1990). In this study, we prepared a series of antibodies against synthetic peptides and fusion products of the mak gene and characterized the subcellular localization, protein kinase activity, and association with other cellular proteins of Mak. Mak products were identified as 66- and 60-kDa proteins that specifically appeared in rat testes after puberty. Testicular germ cell fractionation revealed that Mak products were most abundant in the fraction of the late pachytene stage and that their levels were dramatically decreased in postmeiotic haploid cells. Mak products were localized mostly in the cytoplasm as a soluble form. [S-35] methionine labelling demonstrated that Mak products were associated with a 210-kDa cellular protein; in an in vitro kinase assay with immunoprecipitates of Mak products, the 210-kDa cellular protein was efficiently phosphorylated on serine and threonine residues. Furthermore, in a testicular cell culture system with P-32(i), the 210-kDa molecule associated with Mak was phosphorylated in vivo on serine and threonine residues. These results strongly suggest that the Mak complex may play a role in meiosis during spermatogenesis and that a phosphorylated 210-kDa protein is one of the physiological substrates for this protein kinase.
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页码:4146 / 4156
页数:11
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