The myocardin-related transcription factor, MASTR, cooperates with MyoD to activate skeletal muscle gene expression

Stryder M. Meadows, Andrew S. Warkman, Matthew C. Salanga, Eric M. Small, Paul A. Krieg

Research output: Contribution to journalArticle

18 Scopus citations


The myocardin family proteins (myocardin, MRTF-A, and MRTF-B) are serum response factor (SRF) cofactors and potent transcription activators. Gene-ablation studies have indicated important developmental functions for myocardin family proteins primarily in regulation of cardiac and smooth muscle development. Using Xenopus genome and cDNA databases, we identified a myocardin-related transcription factor expressed specifically in the skeletal muscle lineage. Synteny and sequence alignments indicate that this gene is the frog orthologue of mouse MASTR [Creemers EE, Sutherland LB, Oh J, Barbosa AC, Olson EN (2006) Coactivation of MEF2 by the SAP domain proteins myocardin and MASTR. Mol Cell 23:83-96]. Inhibition of MASTR function in the Xenopus embryo by using dominant-negative constructions or morpholino knockdown results in a dramatic reduction in expression of skeletal muscle marker genes. Overexpression of MASTR in whole embryos or embryonic tissue explants induces ectopic expression of muscle marker genes. Furthermore, MASTR cooperates with the myogenic regulatory factors MyoD and Myf5 to activate transcription of skeletal muscle genes. An essential function for MASTR in regulation of myogenic development in the vertebrate embryo has not been previously indicated.

Original languageEnglish (US)
Pages (from-to)1545-1550
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number5
StatePublished - Feb 5 2008



  • Myf5
  • Serum response factor
  • Xenopus

ASJC Scopus subject areas

  • General

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