Transcription of the alpha2u-globulin gene in male rat liver nuclei in vitro.
Transcription of the alpha2u-globulin gene in male rat liver nuclei in vitro.
复制标题
雄性大鼠肝细胞核中α2u-球蛋白基因的体外转录。
作者：
K. M. Chan;D. T. Kurtz;P. Feigelson
Alpha2u-球蛋白是一种受多激素控制的雄性大鼠肝脏蛋白质，约占肝脏蛋白质合成的 1%。我们使用无核细胞转录系统，以汞化 CTP 作为内源性 RNA 聚合酶的底物，测量了 α2u-球蛋白基因的转录率。新合成的汞化RNA通过巯基琼脂糖层析纯化，不含内源RNA，并与3H标记的α2u-球蛋白cDNA杂交。研究发现，在雄性大鼠肝细胞核中，α2u-球蛋白RNA序列占新合成RNA总量的0.005%。 Actinomycin D 或 α-鹅膏蕈碱完全阻断这些细胞核中 α2u-球蛋白 RNA 的合成。在雌性大鼠肝细胞核中未检测到 α2u-球蛋白 RNA 合成。因此，在我们检测的范围内，雌性大鼠中肝脏α2u-球蛋白mRNA的缺失似乎是由于这些动物中α2u-球蛋白基因转录的缺乏。
Alpha2u-globulin is a male rat liver protein under multihormonal control which represents approximately 1% of hepatic protein synthesis. We have measured the rate of transcription of the alpha2u-globulin gene using a nuclear cell-free transcriptional system with mercurated CTP as substrate for the endogenous RNA polymerases. The newly synthesized, mercurated RNA was purified free of endogenous RNA by chromatography on sulfhydryl agarose and hybridized to 3H-labeled alpha2u-globulin cDNA. It was found that, in male rat liver nuclei, alpha2u-globulin RNA sequences represent 0.005% of the total newly synthesized RNA. Actinomycin D or alpha-amanitin completely blocks the synthesis of alpha2u-globulin RNA in these nuclei. No alpha2u-globulin RNA synthesis was detectable in female rat liver nuclei. Thus, within the limits of our detection the absence of hepatic alpha2u-globulin mRNA in female rats appears to be due to a lack of transcription of the alpha2u-globulin gene in these animals.