Goto M, Tamura T, Mikoshiba K, Masamune Y, Nakanishi Y
Faculty of Pharmaceutical Sciences, Kanazawa University, Ishikawa, Japan.
Nucleic Acids Res. 1991 Jul 25;19(14):3959-63. doi: 10.1093/nar/19.14.3959.
To elucidate the mechanism by which transcription of the somatic-type phosphoglycerate kinase 1 gene is inactivated during mammalian spermatogenesis, we examined the presence of specific transcription inhibitor(s) in the testis by a cell-free transcription system. Transcription of the mouse phosphoglycerate kinase 1 gene using nuclear extracts of the rat liver was significantly inhibited by the addition of testis extracts, whereas brain extracts had little effect. Transcription inhibition required the binding of a testis-specific factor, designated TIN-1, to the region between positions -268 and -259 relative to transcription initiation site at +1. This region had the sequence 5'-AGGAAGTTCC-3' that includes an inverted repeat of the binding motif, 5'-GGAA-3', for the oncoprotein Ets. A UV-crosslinking experiment revealed that 43- and 45-kDa polypeptides present in testis extracts bind to that sequence. These results suggest that a testis-specific transcription inhibitor TIN-1 inactivates the phosphoglycerate kinase 1 gene in the mammalian spermatogenic pathway.
为阐明哺乳动物精子发生过程中体细胞型磷酸甘油酸激酶1基因转录失活的机制，我们通过无细胞转录系统检测了睾丸中特异性转录抑制剂的存在情况。用大鼠肝脏的核提取物进行小鼠磷酸甘油酸激酶1基因的转录时，加入睾丸提取物可显著抑制转录，而脑提取物几乎没有影响。转录抑制需要一种睾丸特异性因子（命名为TIN-1）结合到相对于转录起始位点（+1）的-268至-259位之间的区域。该区域的序列为5'-AGGAAGTTCC-3'，其中包含癌蛋白Ets的结合基序5'-GGAA-3'的反向重复序列。紫外线交联实验表明，睾丸提取物中存在的43 kDa和45 kDa多肽可结合到该序列上。这些结果表明，睾丸特异性转录抑制剂TIN-1在哺乳动物精子发生途径中使磷酸甘油酸激酶1基因失活。
