ID2

Developmental stage

Found in most early fetal tissues but not in the corresponding mature tissues.

Domain

The bHLH domain is essential for its repressor activity towards the CLOCK-BMAL1 heterodimer.

Function

Transcriptional regulator (lacking a basic DNA binding domain) which negatively regulates the basic 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 the CLOCK-BMAL1 heterodimer. Restricts the CLOCK and BMAL1 localization to the cytoplasm. Plays a role in both the input and output pathways of the circadian clock: in the input component, is involved in modulating the magnitude of photic entrainment and in the output component, contributes to the regulation of a variety of liver clock-controlled genes involved in lipid metabolism.

Tissue Specificity

Highly expressed in early fetal tissues, including those of the central nervous system.

Cellular localization

• Cytoplasm
• Nucleus

Alternative names

BHLHB26, ID2, DNA-binding protein inhibitor ID-2, Class B basic helix-loop-helix protein 26, Inhibitor of DNA binding 2, Inhibitor of differentiation 2, bHLHb26

Database links

swissprot:Q02363 entrezGene:3398 omim:600386

Other research areas

• Immunology & Infectious Disease