Lindquester G J, Flach J E, Fleenor D E, Hickman K H, Devlin R B
Emory University, Biology Department, Atlanta, GA 30322.
Nucleic Acids Res. 1989 Mar 11;17(5):2099-118. doi: 10.1093/nar/17.5.2099.
Sequence analysis of overlapping fragments from a quail genomic library has revealed a tropomyosin gene consisting of 13 exons spaced over about 18 kilobase pairs of DNA. Skeletal muscle and smooth muscle transcripts share the same 5' untranslated sequence and may initiate from the same promoter. However, the regions encoding amino acids 39-80 and 258-284 are specific to each muscle type. The two sets of exons encoding these regions undergo mutually exclusive alternative splicing in a tissue-specific manner as determined by Northern blots and S1-nuclease protection. Similarly, the 3' ends of the transcripts are different in skeletal muscle and smooth muscle, and each contains two polyadenylation signals which appear to be utilized in vivo. The avian alpha-tropomyosin gene is not expressed in cardiac muscle. The sequence of the gene shows great homology with other muscle-specific tropomyosins and includes a region homologous to the amino terminus of nonmuscle tropomyosins.
对鹌鹑基因组文库中重叠片段的序列分析揭示了一个原肌球蛋白基因，该基因由13个外显子组成，分布在约18千碱基对的DNA上。骨骼肌和平滑肌转录本共享相同的5'非翻译序列，并且可能从同一个启动子起始。然而，编码氨基酸39 - 80和258 - 284的区域对每种肌肉类型是特异的。通过Northern印迹和S1核酸酶保护分析确定，编码这些区域的两组外显子以组织特异性方式进行相互排斥的可变剪接。同样，骨骼肌和平滑肌中转录本的3'末端也不同，并且每个都包含两个在体内似乎被利用的聚腺苷酸化信号。禽类α - 原肌球蛋白基因在心肌中不表达。该基因的序列与其他肌肉特异性原肌球蛋白具有高度同源性，并且包括一个与非肌肉原肌球蛋白氨基末端同源的区域。
