Production and properties of vitamin-D-induced mRNA for chick calcium-binding protein.
Production and properties of vitamin-D-induced mRNA for chick calcium-binding protein.
复制标题
维生素 D 诱导的鸡钙结合蛋白 mRNA 的产生和特性。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
J. S. Emtage
中科院分区：
文献类型：
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作者：
R. Spencer;M. Charman;D. Lawson;J. S. Emtage
1. 给缺乏维生素 D 的鸡注射 1,25-二羟基胆钙化醇 2 小时内，诱导鸡肠道多核糖体上钙结合蛋白的合成。诱导是短暂的：注射激素后 13 小时达到结合蛋白的最大输出，此后迅速下降。 2. 钙结合蛋白合成的诱导是通过产生该蛋白的活性 mRNA 来实现的。该mRNA在变性条件下的沉降系数为18S，相当于分子量约700000，分子中含有一段聚腺苷酸。 3. 从肠道多核糖体中提取的多核糖体和含 Poly(A) 的 RNA 均刺激小麦胚芽无细胞系统合成一系列蛋白质（分子量高达 70000）。免疫沉淀钙结合蛋白是从服用 1,25-二羟基胆钙化醇的鸟类而非对照鸟类获得的 RNA 中翻译而来的。这种钙结合蛋白与正宗的小鸡钙结合蛋白大小相同（27000分子量）；抗血清不会特异性沉淀其他蛋白质。因此，在鸡中，1,25-二羟基胆钙化醇诱导的钙结合蛋白不是通过任何前体分子合成的。讨论了该结果的含义。
1. Calcium-binding protein synthesis on chick intestinal polysomes is induced within 2 h of injecting vitamin-D-deficient birds with 1,25-dihydroxycholecalciferol. The induction is short-lived: the maximum output of the binding protein is reached by 13 h after hormone injection, and declines rapidly thereafter. 2. This induction of calcium-binding protein synthesis occurs by the production of active mRNA for the protein. The sedimentation coefficient of this mRNA in denaturing conditions is 18 S, equivalent to a molecular weight of approximately 700000, and the molecule contains a tract of polyadenylate. 3. Both polysomal and poly(A)-containing RNA extracted from intestinal polysomes stimulate the synthesis of a range of proteins (up to 70000 molecular weight) by the wheat germ cell-free system. Immunoprecipitable calcium-binding protein is translated from RNA obtained from 1,25-dihydroxycholecalciferol-dosed birds but not from control birds. This calcium-binding protein is the same size (27000 molecular weight) as authentic chick calcium-binding protein; No other proteins are specifically precipitated by the antiserum. Thus in chickens 1,25-dihydroxycholecalciferol-induced calcium-binding protein is not synthesised via any precursor molecule. The implications of this result are discussed.