Tu C P, Weiss M J, Li N Q, Reddy C C
J Biol Chem. 1983 Apr 25;258(8):4659-62.
Tissue-specific patterns of rat glutathione S-transferase expression have been demonstrated by in vitro translation of purified poly(A) RNAs and by protein purification. Poly(A) RNAs from six rat tissues including heart, kidney, liver, lung, spleen, and testis were used to program in vitro translation with the rabbit reticulocyte lysate system and [35S]methionine. The glutathione S-transferase subunits synthesized in vitro were purified from the translation products by affinity chromatography on S-hexylglutathione-linked Sepharose 6B columns. The affinity bound fractions were analyzed by Na dodecyl SO4-polyacrylamide gel electrophoresis and fluorography. A subunit of Mr = 22,000 detected in the in vitro translation products of poly(A) RNAs from heart, kidney, lung, spleen, and testis is missing from the translation products of liver poly(A) RNAs. This Mr = 22,000 subunit is present only in the anionic glutathione S-transferase fraction purified from rat heart, kidney, lung, spleen, and testis. Purified anionic glutathione S-transferase from rat liver does not contain this subunit. The relative specific activities toward a dozen different substrates also demonstrate the nonidentity between liver and kidney anionic glutathione S-transferases. In addition, among the glutathione S-transferase subunits expressed in the liver, some of them could not be detected in the other tissues investigated. Our results indicate that tissue-specific expression of rat glutathione S-transferases may occur pretranslationally.
通过纯化的聚腺苷酸（poly(A)）RNA的体外翻译和蛋白质纯化，已证明大鼠谷胱甘肽S-转移酶表达的组织特异性模式。使用来自大鼠六种组织（包括心脏、肾脏、肝脏、肺、脾脏和睾丸）的聚腺苷酸RNA，在兔网织红细胞裂解物系统中用[35S]甲硫氨酸进行体外翻译编程。体外合成的谷胱甘肽S-转移酶亚基通过在S-己基谷胱甘肽连接的琼脂糖6B柱上的亲和色谱从翻译产物中纯化。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和荧光自显影分析亲和结合的组分。在心脏、肾脏、肺、脾脏和睾丸的聚腺苷酸RNA的体外翻译产物中检测到的Mr = 22,000的亚基在肝脏聚腺苷酸RNA的翻译产物中缺失。这个Mr = 22,000的亚基仅存在于从大鼠心脏、肾脏、肺、脾脏和睾丸纯化的阴离子谷胱甘肽S-转移酶组分中。从大鼠肝脏纯化的阴离子谷胱甘肽S-转移酶不包含该亚基。对十几种不同底物的相对比活性也证明了肝脏和肾脏阴离子谷胱甘肽S-转移酶之间的非同一性。此外，在肝脏中表达的谷胱甘肽S-转移酶亚基中，有些在其他研究的组织中无法检测到。我们的结果表明，大鼠谷胱甘肽S-转移酶的组织特异性表达可能在翻译前发生。
