MYF-6, A NEW MEMBER OF THE HUMAN GENE FAMILY OF MYOGENIC DETERMINATION FACTORS - EVIDENCE FOR A GENE-CLUSTER ON CHROMOSOME-12
MYF-6, A NEW MEMBER OF THE HUMAN GENE FAMILY OF MYOGENIC DETERMINATION FACTORS - EVIDENCE FOR A GENE-CLUSTER ON CHROMOSOME-12
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DOI：
10.1002/j.1460-2075.1990.tb08179.x
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发表时间：
1990-03-01
期刊：
影响因子：
11.4
通讯作者：
ARNOLD, HH
中科院分区：
文献类型：
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作者：
BRAUN, T;BOBER, E;ARNOLD, HH
Myf-6基因是人类肌肉决定因子基因家族的一个新成员，其高度保守的序列编码一个假定的螺旋-环-螺旋结构域。这个序列基序是所有Myf因子和其他调节蛋白的共同特征。新的Myf基因位于人类12号染色体。apprx上。位于Myf-5位点上游6.5 Kb处，位于肌源性决定基因紧密相连的基因簇中。Myf-6 cdna是从人和小鼠骨骼肌中分离出来的，骨骼肌是唯一观察到相应mRNA表达的组织。与表达中等水平Myf-6 mRNA的人类原代肌肉细胞培养相反，大多数已建立的啮齿动物肌肉细胞系完全缺乏这种mRNA。然而，通过表达pEMSV - Myf-4或pEMSV - Myf-5诱导的肌源性10T1/2细胞激活其内源性小鼠Myf-6基因。在C3H 10T1/2成纤维细胞中，Myf-6 cDNA在C3H中的组成性表达建立了肌肉表型，其频率与先前表征的肌源性因子相似。此外，含有人肌球蛋白轻链（MLC）增强子或胚胎肌球蛋白轻链基因启动子的肌肉特异性CAT报告构建物在NIH 3T3成纤维细胞或CV1肾细胞中通过Myf-6表达载体的共转染被激活。这种转录激活发生在没有任何明显的细胞表型转换的受体细胞。与Myf-3、Myf-4或Myf-5的谷胱甘肽- s转移酶融合蛋白特异性结合人MLC增强子和MLC1 emb启动子中存在的mef样一致序列。相比之下，Myf-6杂交蛋白与相同序列的相互作用较弱，表现出较低的亲和力和降低的特异性。然而，由于共表达的pEMSV - Myf-6能够在非肌肉组织培养细胞中激活MLC-CAT报告基因的转录，因此，体外不同的DNA结合特性可能表明，Myf-6对基因表达的反式激活涉及不同的结合位点和/或其他蛋白质因子。
The Myf-6 gene, a novel member of the human gene family of muscle determination factors has been detected by its highly conserved sequence coding for a putative helix-loop-helix domain. This sequence motif is a common feature of all Myf factors and other regulatory proteins. The new Myf gene is located on human chromosome 12, .apprx. 6.5 Kb upstream of the Myf-5 locus in a closely linked cluster of myogenic determination genes. Myf-6 cDNAs were isolated from human and mouse skeletal muscle, the only tissue in which expression of the corresponding mRNA was observed. In contrast to human primary muscle cell cultures which express moderate levels of Myf-6 mRNA, most established rodent muscle cell lines completely lack this mRNA. Myogenic 10T1/2 cells, however, induced by the expression of either pEMSV - Myf-4 or pEMSV - Myf-5 activate their endogenous mouse Myf-6 gene. Constitutive expression of Myf-6 cDNA in C3H in C3H 10T1/2 fibroblasts establishes the muscle phenotype at a similar frequency to the previously characterized myogenic factors. Moreover, muscle-specific CAT reporter constructs containing either the human myosin light chain (MLC) enhancer or the promoter of the embryonic myosin light chain gene are activated in NIH 3T3 fibroblasts or in CV1 kidney cells by cotransfection of Myf-6 expression vehicles. This transriptional activation occurs in the absence of any apparent conversion of the cellular phenotype of the recipient cells. Glutathione-S-transferase fusion proteins with Myf-3, Myf-4 or Myf-5 specifically bind to a MEF-like consensus sequence present in the human MLC enhancer and the MLC1 emb promoter. In contrast, the Myf-6 hybrid protein interacts weakly with the same sequences showing lower affinity and reduced specificity. Since co-expressed pEMSV - Myf-6, nevertheless, is able to activate transcription of the MLC-CAT reporter constructs in non-muslce tissue culture cells, the different DNA binding properties in vitro might suggest that trans-activation of gene expression by Myf-6 involves distinct binding sites and/or additional protein factors.