Molecular distinction between specification and differentiation in the myogenic basic helix-loop-helix transcription factor family

作     者：Bergstrom, DA Tapscott, SJ 

作者机构：Fred Hutchinson Canc Res Ctr Div Human Biol Program Dev Biol Seattle WA 98108 USA Univ Washington Sch Med Dept Pathol Seattle WA 98195 USA Univ Washington Sch Med Dept Neurol Seattle WA 98195 USA 

出 版 物：《MOLECULAR AND CELLULAR BIOLOGY》 (分子生物学与细胞生物学)

年 卷 期：2001年第21卷第7期

页      面：2404-2412页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：NIAMS NIH HHS [AR45113  R01 AR045113] Funding Source: Medline 

主　　题：.efficient distinction Myf Basic helix-loop-helix myogenic bHLH Specification and Differentiation skeletal muscle genes MyoD and myogenin MyoD helix 

摘      要：The myogenic basic helix-loop-helix (bHLH) proteins regulate both skeletal muscle specification and differentiation: MyoD and Myf5 establish the muscle lineage, whereas myogenin mediates differentiation. Previously, we demonstrated that MyoD was more efficient than myogenin at initiating the expression of skeletal muscle genes, and in this study we present the molecular basis for this difference. A conserved amphipathic alpha-helix in the carboxy terminus of the myogenic bHLH proteins has distinct activities in MyoD and myogenin: the MyoD helix facilitates the initiation of endogenous gene expression, whereas the myogenin helix functions as a general transcriptional activation domain. Thus, the alternate use of a similar motif for gene initiation and activation provides a molecular basis for the distinction between specification and differentiation within the myogenic bHLH gene family.