MHox: a mesodermally restricted homeodomain protein that binds an essential site in the muscle creatine kinase enhancer.
MHox: a mesodermally restricted homeodomain protein that binds an essential site in the muscle creatine kinase enhancer.
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发表时间：
1992-08
期刊：
影响因子：
4.6
通讯作者：
P. Cserjesi;Brenda Lilly;Laura Bryson;Yaoqi Wang;David Sassoon;E. N. Olson
中科院分区：
文献类型：
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作者：
P. Cserjesi;Brenda Lilly;Laura Bryson;Yaoqi Wang;David Sassoon;E. N. Olson
肌源性螺旋-环-螺旋（HLH）蛋白，如myogenin和MyoD，当引入各种非肌肉细胞类型时，可以激活肌肉特异性转录。虽然中胚层细胞对这些肌生成调节因子的作用特别允许，但许多其他类型的细胞对它们的肌生成转化是不耐受的。在这里，我们描述了一种新的同源结构域蛋白MHox，它结合了肌肉肌酸激酶（MCK）增强子中富含a + t的元素，这对于肌肉特异性转录和肌源性HLH蛋白的反式激活至关重要。在胚胎发生过程中，MHox完全局限于中胚层来源的细胞类型和已建立的中胚层来源的细胞系。与大多数其他同源盒基因不同，MHox在神经系统中不表达，在肢体芽和内脏弓中表达水平最高。在成年小鼠中，MHox在骨骼肌、心脏和子宫中高水平表达。MHox的dna结合特性和表达模式在同源盒基因中是独一无二的，这表明MHox作为一种转录调节因子参与了多种中胚层细胞类型的建立。
Myogenic helix-loop-helix (HLH) proteins, such as myogenin and MyoD, can activate muscle-specific transcription when introduced into a variety of nonmuscle cell types. Whereas cells of mesodermal origin are especially permissive to the actions of these myogenic regulators, many other cell types are refractory to myogenic conversion by them. Here we describe a novel homeodomain protein, MHox, that binds an A+T-rich element in the muscle creatine kinase (MCK) enhancer that is essential for muscle-specific transcription and trans-activation by myogenic HLH proteins. MHox is completely restricted to mesodermally derived cell types during embryogenesis and to established cell lines of mesodermal origin. In contrast to most other homeobox genes, MHox expression is excluded from the nervous system, with the highest levels observed in limb bud and visceral arches. In adult mice, MHox is expressed at high levels in skeletal muscle, heart and uterus. The DNA-binding properties and pattern of MHox expression are unique among homeobox genes and suggest a role for MHox as a transcriptional regulator that participates in the establishment of diverse mesodermal cell types.