DNA-binding protein inhibitor ID-2 (ID2)

Transcriptional regulator (lacking a basic DNA binding domain) which negatively regulates the simple helix-loop-helix (bHLH) transcription factors by forming heterodimers and inhibiting their DNA binding and transcriptional activity. Implicated in regulating a variety of cellular processes, including cellular growth, senescence, differentiation, apoptosis, angiogenesis, and neoplastic transformation.

Inhibits skeletal muscle and cardiac myocyte differentiation. Regulates the circadian clock by repressing the transcriptional activator activity of this CLOCK-ARNTL/BMAL1 heterodimer.