ID4 Proteins and Enzymes

Transcription factors containing a basic helix-loop-helix (bHLH) motif regulate expression of tissue-specific genes ina number of mammalian and insect systems. DNA-binding activity of the bHLH proteins is dependent on formation of homo-and/or heterodimers. Dominant-negative HLH proteins encoded by Id-related genes, such as ID4, also contain theHLH-dimerization domain but lack the DNA-binding basic domain. Consequently, Id proteins inhibit binding to DNA andtranscriptional transactivation by heterodimerization with bHLH proteins (Pagliuca et al., 1995 (PubMed7665172)).(supplied by OMIM)