Affordable Access

Molecular Distinction between Specification and Differentiation in the Myogenic Basic Helix-Loop-Helix Transcription Factor Family

Authors
  • Donald A. Bergstrom
  • Stephen J. Tapscott
Publisher
American Society for Microbiology
Publication Date
Apr 01, 2001
Source
PMC
Keywords
Disciplines
  • Biology
License
Unknown

Abstract

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.

Report this publication

Statistics

Seen <100 times