Identification of members of the protein phosphatase 1 gene family in the rat and enhanced expression of protein phosphatase 1 alpha gene in rat hepatocellular carcinomas.
Identification of members of the protein phosphatase 1 gene family in the rat and enhanced expression of protein phosphatase 1 alpha gene in rat hepatocellular carcinomas.
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DOI：
10.1111/j.1349-7006.1990.tb02690.x
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发表时间：
1990-12
期刊：
影响因子：
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通讯作者：
Nagao M
中科院分区：
文献类型：
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作者：
Sasaki K;Shima H;Kitagawa Y;Irino S;Sugimura T;Nagao M
我们从大鼠肝脏和睾丸cDNA文库中分离了4种蛋白磷酸酶1（PP-1）催化亚基亚型的cDNA克隆。为了克隆，使用编码小鼠PP-1催化亚基的dis 2 ml和dis 2 m2的cDNA片段作为探针。四种同种型中的两种被认为来自同一基因，并通过选择性剪接产生。根据核苷酸序列和推导的氨基酸序列与文献报道的比较，将这些cDNA克隆分别命名为大鼠PP-1α、PP-1γ1、PP-1γ2和PP-δ。这4个cDNA克隆推导的氨基酸序列同源性在90%左右。它们的氨基末端区域高度保守，差异主要在羧基末端区域。此外，位于肽中间区域的几个氨基酸在PP-1、PP-2A、PP-2B和PP-2C的催化亚基的所有同种型中是保守的。这些保守区域被认为是蛋白磷酸酶催化亚基的功能结构域。2-氨基-3，8-二甲基咪唑并[4，5-f]喹喔啉诱发大鼠肝癌后，PP-1α表达增加，PP-1γ1、PP-1γ2和PP-1δ表达无增加。PP-1α可能参与肝癌发生或肝细胞增殖。
We isolated four kinds of cDNA clones of isotypes of catalytic subunits of protein phosphatase 1 (PP‐1) from rat liver and testis cDNA libraries. For the cloning, cDNA fragments of dis2ml and dis2m2, which encode mouse PP‐1 catalytic subunits, were used as probes. Two of the four isotypes were thought to be derived from the same gene and produced by alternative splicing. Based on the comparative study of their nucleotide and deduced amino acid sequences with those reported, these cDNA clones were named rat PP‐1α, PP‐1γ1, PP‐1γ2 and PP‐δ. The deduced amino acid sequences of these four cDNA clones showed about 90% identity. Their amino‐terminal regions were highly conserved, and their differences were mainly in the carboxy‐terminal regions. Furthermore, several amino acids located in the middle regions of the peptides were conserved in all the isotypes of the catalytic subunits of PP‐1, PP‐2A, PP‐2B and PP‐2C. These conserved regions are suggested to be the functional domains of the catalytic subunits of protein phosphatases. Rat hepatocellular carcinomas induced by a food mutagen, 2‐amino‐3,8‐dimethylimidazo[4,5‐f]quinoxaline showed increased expression of PP‐1α, but no increased expression of PP‐1γ1, PP‐1γ2 or PP‐1δ. Involvement of PP‐1α in hepatocarcinogenesis or in hepatic cell proliferation was suspected.