Mayer Y, Czosnek H, Zeelon P E, Yaffe D, Nudel U
Nucleic Acids Res. 1984 Jan 25;12(2):1087-100. doi: 10.1093/nar/12.2.1087.
Several types of evidence indicate that the gene coding for the skeletal muscle actin is expressed in the rat heart: 1) A recombinant plasmid containing an insert with a nucleotide sequence identical to that of the homologous region of skeletal muscle actin gene was isolated from a cDNA library prepared on rat cardiac mRNA template. 2) Using specific probes it was found that the hearts of newborn rats contain a significant amount of skeletal muscle actin mRNA. The quantity of this mRNA in the heart decreases during development. 3) The skeletal muscle actin gene is DNAase I sensitive in nuclei from rat heart tissue. A plasmid containing a cDNA insert homologous to a part of the cardiac actin mRNA was isolated and sequenced. It was found that in spite of the great similarity between the amino acid sequence of the skeletal muscle and cardiac actins, the nucleotide sequences of the two mRNAs are considerably divergent. There is only limited sequence homology between the 3' untranslated regions of the two mRNAs. However, there is an extensive sequence homology between the 3' untranslated regions of the rat and human cardiac mRNAs, suggesting a functional role for this region of the gene or mRNA.
有几种证据表明，编码骨骼肌肌动蛋白的基因在大鼠心脏中表达：1）从以大鼠心脏mRNA为模板制备的cDNA文库中分离出一个重组质粒，其插入片段的核苷酸序列与骨骼肌肌动蛋白基因同源区域的核苷酸序列相同。2）使用特异性探针发现，新生大鼠心脏中含有大量骨骼肌肌动蛋白mRNA。心脏中这种mRNA的数量在发育过程中减少。3）骨骼肌肌动蛋白基因在大鼠心脏组织的细胞核中对DNA酶I敏感。分离并测序了一个含有与心脏肌动蛋白mRNA一部分同源的cDNA插入片段的质粒。结果发现，尽管骨骼肌肌动蛋白和心脏肌动蛋白的氨基酸序列非常相似，但这两种mRNA的核苷酸序列却有很大差异。两种mRNA的3'非翻译区之间只有有限的序列同源性。然而，大鼠和人类心脏mRNA的3'非翻译区之间存在广泛的序列同源性，这表明该基因或mRNA的这一区域具有功能作用。
