STRUCTURE AND EXPRESSION OF HUMAN ACTIN GENES

肌动蛋白是所有真核细胞的主要成分。从功能上讲，它们是 参与细胞骨架结构，这些结构在 转化的细胞。为了理解人类的结构和表情 肌动蛋白基因，我们已经开始对分子克隆的人类进行分子分析 肌动蛋白基因。人平滑肌肌动蛋白基因的DNA序列分析 (大动脉类型)表明该基因有一个独特的内含子，在任何 对其他肌动蛋白基因的分析表明，该内含子插入的时间较晚 在进化过程中。肌动蛋白基因在化学研究中的应用 转化的人类细胞显示出在正常情况下没有发现的点突变 细胞对应物。 研究克隆的人心脏肌动蛋白DNA是否含有序列 为获得表达所必需的基因，构建了重组表达载体 将心脏肌动蛋白DNA插入表达穿梭载体牛 乳头状瘤病毒DNA。用该重组蛋白转化小鼠细胞 表达了大量的人类心脏信使核糖核酸，这种信使核糖核酸 在小鼠细胞中忠实地翻译成心脏肌动蛋白。结果是 表明克隆的肌动蛋白DNA包含(在其5‘和3’之间 未翻译序列)信号，用于启动和终止 抄写和翻译也是如此。牛乳头状瘤病毒DNA 载体可用于在小鼠中稳定表达克隆的人DNA序列 细胞。

Actins are major components of all eukaryotic cells. Functionally they are involved in the cytoskeletal structures and these structures are altered in transformed cells. To understand the structure and expression of the human actin genes, we have begun a molecular analysis of molecularly cloned human actin genes. DNA sequence analysis of the human smooth muscle actin gene (aortic type) showed that this gene has a unique intron not found in any other actin genes analyzed, suggesting that this intron was inserted late in the evolutionary process. The smooth muscle actin gene in chemically transformed human cells showed a point mutation not found in the normal cell counterpart. To study whether the cloned human cardiac actin DNA contained sequences necessary for its expression, a recombinant plasmid was constructed by inserting the cardiac actin DNA into the expression shuttle vector, bovine papilloma viral DNA. Mouse cells transformed with this recombinant expressed a substantial amount of the human cardiac mRNA and this mRNA was faithfully translated into cardiac actin in mouse cells. The results indicate that the cloned actin DNA contains (within its 5' and 3' untranslated sequences) signals for the initiation and termination of transcription as well as for translation. Bovine papilooma viral DNA vectors can be used to stably express cloned human DNA sequences in mouse cells.