Conneely O M, Kettelberger D M, Tsai M J, Schrader W T, O'Malley B W
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
J Biol Chem. 1989 Aug 25;264(24):14062-4.
The chicken progesterone receptor A and B proteins differ by an additional 128 amino acids located at the N terminus of the B protein. Using site-directed mutagenesis, we demonstrate that these two proteins arise by alternate initiation of translation from two in-phase AUG codons located on a single mRNA transcript. Both proteins are transcriptionally active in terms of their ability to activate a progesterone-responsive target gene. These results suggest a functional significance for evolutionary conservation of two forms of this steroid receptor.
鸡孕激素受体A和B蛋白在B蛋白N端另有128个氨基酸的差异。我们通过定点诱变证明，这两种蛋白是由位于单个mRNA转录本上的两个同相位AUG密码子交替起始翻译产生的。就激活孕激素反应性靶基因的能力而言，这两种蛋白均具有转录活性。这些结果表明了这种类固醇受体两种形式进化保守性的功能意义。
