bHLHb20, Class B basic helix-loop-helix protein 20, DNA binding protein HTF4, DNA-binding protein HTF4, E box binding protein, E-box-binding protein, HEB, HTF4, HTF4_HUMAN, TCF-12, Tcf12, Transcription factor 12, Transcription factor HTF-4, Transcription factor HTF4.
Differentiation of myogenic cells is regulated by multiple positively and negatively acting factors. One well characterized family of helix-loop-helix (HLH) proteins known to play an important role in the regulation of muscle cell development includes Myo D, myogenin, Myf-5 and Myf-6 (also designated MRF-4 or herculin). Myo D transcription factors form heterodimers with products of a more widely expressed family of bHLH genes, the E family, which consists of at least three distinct genes: E2A, IF2 and HEB. Myo D-E heterodimers bind avidly to consensus (CANNTG) E box target sites that are functionally important elements in the upstream regulatory sequences of many muscle-specific terminal differentiation genes. Both homo- and hetero-oligomers of these proteins are able to distinguish very closely related E box proteins and are believed to play important roles in lineage specific gene expression.
