Suguoka Y, Kano T, Okuda A, Sakai M, Kitagawa T, Muramatsu M
Nucleic Acids Res. 1985 Sep 11;13(17):6049-57. doi: 10.1093/nar/13.17.6049.
A cDNA library prepared from poly(A)+ RNA of 2-acetylaminofluorene (AAF) induced rat hepatocellular carcinoma was screened by synthetic DNA probes deduced from a partial amino acid sequence of glutathione S-transferase P subunit that had been isolated from the tumor by two-dimensional gel electrophoresis. One of the four clones analyzed contained an mRNA region encoding the total amino acid sequence of this enzyme subunit and the complete 3'-noncoding region. The nucleotide sequence indicates that this enzyme subunit has 209 amino acids (calculated Mr=23,307) distinct from other glutathione S-transferase subunits such as Ya and Yc. Comparison of the amino acid sequences between these proteins indicates that glutathione S-transferase P subunit gene has been evolved from the ancestral gene at an earlier stage than the separation of Ya and Yc and that there are at least three domains having a considerable homology with each other in these enzymes. The very large increase of this mRNA in chemically induced hepatocellular carcinoma suggests a characteristic derepression of this gene during hepatocarcinogenesis.
用从二维凝胶电泳分离出的谷胱甘肽S-转移酶P亚基的部分氨基酸序列推导的合成DNA探针，筛选从2-乙酰氨基芴（AAF）诱导的大鼠肝细胞癌的聚腺苷酸加尾RNA制备的cDNA文库。分析的四个克隆之一包含一个编码该酶亚基总氨基酸序列和完整3'非编码区的mRNA区域。核苷酸序列表明该酶亚基有209个氨基酸（计算的Mr = 23,307），与其他谷胱甘肽S-转移酶亚基如Ya和Yc不同。这些蛋白质之间氨基酸序列的比较表明，谷胱甘肽S-转移酶P亚基基因比Ya和Yc分离的早期阶段从祖先基因进化而来，并且在这些酶中至少有三个结构域彼此具有相当大的同源性。这种mRNA在化学诱导的肝细胞癌中的大量增加表明该基因在肝癌发生过程中具有特征性的去抑制作用。
