Kropp K E, Gulick J, Robbins J
Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Ohio 45267-0575.
J Biol Chem. 1987 Dec 5;262(34):16536-45.
Recently we have isolated a large number of chicken myosin or myosin-like heavy chain genes. Seven of these genes were placed into a subset based upon their hybridization patterns. In the present study, the sequence of the 5' end of one of the myosin heavy chain (MHC) genes, N127, was determined and compared with the 5' end sequences of the other six MHC genes in the subset. The comparison revealed that the three exons encoding the amino termini of the protein are highly conserved. The sequence analysis shows that a localized correction event occurred in and around a domain of the nucleotide-binding site, as the exon encoding this site and the preceding intron are very highly conserved among the seven genes. The sequence of the promoter and 5'-untranslated region of N127 is presented. The analogous regions for N124 and N125 have now been sequenced and are also presented. As is the case for all the other known MHC genes, the 5'-untranslated regions are split by large introns. The promoter and 5'-untranslated regions are compared with two previously characterized chicken MHC genes (N116 and N118) to determine the sequence similarities and differences that might underlie the differential expression of the family's members. To confirm and extend previously published results of the expression of these genes, transcript-specific probes generated from the 5' region of six of the seven genes were used to determine in which muscle(s) the corresponding mRNAs were present. The data show that despite the very close structural homologies, each of the genes for which a unique probe could be prepared exhibits a unique pattern of expression.
最近我们分离出了大量鸡肌球蛋白或类肌球蛋白重链基因。根据杂交模式，其中七个基因被归入一个子集。在本研究中，测定了其中一个肌球蛋白重链（MHC）基因N127的5'端序列，并与该子集中其他六个MHC基因的5'端序列进行了比较。比较结果显示，编码该蛋白氨基末端的三个外显子高度保守。序列分析表明，在核苷酸结合位点的一个结构域及其周围发生了局部校正事件，因为编码该位点的外显子和前面的内含子在这七个基因中高度保守。给出了N127的启动子和5'非翻译区的序列。N124和N125的类似区域现已测序并也已给出。与所有其他已知的MHC基因一样，5'非翻译区被大的内含子分隔。将启动子和5'非翻译区与两个先前已鉴定的鸡MHC基因（N116和N118）进行比较，以确定可能是该家族成员差异表达基础的序列异同。为了证实并扩展先前发表的这些基因表达的结果，使用从七个基因中的六个基因的5'区域产生的转录本特异性探针来确定相应的mRNA存在于哪些肌肉中。数据表明，尽管结构上非常相似，但每个能够制备独特探针的基因都表现出独特的表达模式。
