Myocyte enhancer factor 2 (MEF2)

The Myocyte Enhancer Factor 2 (MEF2) proteins are transcription factors expressed during development of all three muscle lineages. Of the four mammalian mef2 genes, three (A, C and D) can be alternatively spliced, producing transcripts and proteins which may have significant functional differences, Specific binding sites for MEF2 proteins have been characterized in many striated muscle genes and MEF2 proteins can trans-activate gene expression both as home-and heterodimers. Loss-of-function mutants in Drosophila indicate that MEF2 is an essential co-factor, but not a primary determinent, in the development of all three muscle lineages in the fly, Recent data suggest an interaction between the DNA-binding domains of mammalian MEF2 proteins and those of tissue-specific basic helix-loop-helix (bHLH) factors and thyroid hormone receptor alpha 1 (TR alpha 1) in the expression of target genes and the development of specific cell phenotypes. Understanding how MEF2 proteins function in the three mammalian muscle types may allow the development of therapeutic strategies for manipulating muscle growth and characteristics. (C) 1997 Elsevier Science Ltd. All rights reserved.