Spicer D B, Rhee J, Cheung W L, Lassar A B
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Science. 1996 Jun 7;272(5267):1476-80. doi: 10.1126/science.272.5267.1476.
The myogenic basic helix-loop-helix (bHLH) and MEF2 transcription factors are expressed in the myotome of developing somites and cooperatively activate skeletal muscle gene expression. The bHLH protein Twist is expressed throughout the epithelial somite and is subsequently excluded from the myotome. Ectopically expressed mouse Twist (Mtwist) was shown to inhibit myogenesis by blocking DNA binding by MyoD, by titrating E proteins, and by inhibiting trans-activation by MEF2. For inhibition of MEF2, Mtwist required heterodimerization with E proteins and an intact basic domain and carboxyl-terminus. Thus, Mtwist inhibits both families of myogenic regulators and may regulate myotome formation temporally or spatially.
生肌碱性螺旋-环-螺旋（bHLH）和MEF2转录因子在发育中的体节的肌节中表达，并协同激活骨骼肌基因表达。bHLH蛋白Twist在整个上皮体节中表达，随后被排除在肌节之外。异位表达的小鼠Twist（Mtwist）被证明可通过阻断MyoD与DNA的结合、滴定E蛋白以及抑制MEF2的反式激活来抑制肌生成。为了抑制MEF2，Mtwist需要与E蛋白异源二聚化以及完整的碱性结构域和羧基末端。因此，Mtwist抑制这两个生肌调节因子家族，并可能在时间或空间上调节肌节形成。
