Developmental expression and cardiac transcriptional regulation of Myh7b, a third myosin heavy chain in the vertebrate heart.
Developmental expression and cardiac transcriptional regulation of Myh7b, a third myosin heavy chain in the vertebrate heart.
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DOI：
10.1002/cm.21029
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发表时间：
2012-05
期刊：
影响因子：
--
通讯作者：
Krieg PA
中科院分区：
文献类型：
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作者：
Warkman AS;Whitman SA;Miller MK;Garriock RJ;Schwach CM;Gregorio CC;Krieg PA
哺乳动物心脏表达两个肌球蛋白重链基因(MYH6和MyH7)，这两个基因是肌节粗丝的主要成分。我们已经确定，第三个肌球蛋白重链MYH7B也在心肌中表达。发育分析表明，Myh7b在非洲爪哇、鸡和小鼠胚胎的心肌和骨骼肌中表达，在小鼠胚胎发育的后期在平滑肌组织中表达。Myh7b在成人心脏中也有表达。Myh7b基因的启动子区域在不同物种之间具有显著的相似性，这表明转录调控机制是保守的。利用大鼠心肌细胞的荧光素酶报告分析，可以证明MEF2、GATA和E-box调控元件是Myh7b基因高效表达所必需的。此外，两个与已知转录因子的共识结合位点不对应的保守元件也是Myh7b报告基因充分转录活性所必需的。最后，Myh7b基因在心肌肥大时表现出类似于MYH6的转录反应。
The mammalian heart expresses two myosin heavy chain genes (Myh6 and Myh7), which are major components of the thick filaments of the sarcomere. We have determined that a third myosin heavy chain, MYH7B, is also expressed in the myocardium. Developmental analysis shows Myh7b expression in cardiac and skeletal muscle of Xenopus, chick and mouse embryos, and in smooth muscle tissues during later stages of mouse embryogenesis. Myh7b is also expressed in the adult human heart. The promoter region of the Myh7b gene shows remarkable similarity between diverse species, suggesting that transcriptional control mechanisms have been conserved. Using luciferase reporter analysis in rat cardiomyocytes, it can be shown that MEF2, GATA and E-box regulatory elements are essential for efficient expression of the Myh7b gene. In addition two conserved elements that do not correspond to consensus binding sites for known transcription factors are also essential for full transcriptional activity of the Myh7b reporter. Finally, the Myh7b gene shows a transcriptional response similar to Myh6 in response to cardiac hypertrophy.