Mef2

Myocyte Enhancer Factor-2 (MEF2) is a MADS-box and MEF2 DNA-binding domains. Many, if not all, members of the MEF2 family are required for proper development of an embryo.

MEF2 was originally identified as a transcription factor in Drosophila (sometimes called D-MEF2) through enhancer region.

While Drosophila has the single MEF2 gene, Vertebrates have four versions of the Mef2 gene (Mef2a, Mef2b, expressed in distinct but overlapping patterns during embryogenesis through adulthood.^[1] All of the mammalian Mef2 genes share approximately 50% overall amino acid identity and about 95% similarity throughout the highly conserved N-terminal MADS-box and MEF2 domains, however their sequences diverge in their C-terminal transactivation domain.^[2] The MADS-box serves as the minimal DNA-binding domain, however an adjacent 29-amino acid extension called the MEF2 domain is required for high affinity DNA-binding and dimerization. Through an interaction with the MADS-box, MEF2 transcription factors have the ability to homo- and heterodimerize,^[3] and a classic nuclear localization sequence (NLS) in the C-terminus of MEF2A, -C, and – D ensures nuclear localization of the protein.^[4] Interestingly, D-MEF2 and MEF2B lack this conserved NLS but are still found in the nucleus.^[5]

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