Inhibitor of DNA binding 2B (ID2B)

Inhibitor of DNA binding 2B (ID2B) is a member of the helix-loop-helix family of transcriptional regulators, primarily identified in fish and zebrafish genomes. It acts as a dominant-negative modulator by binding and inactivating bHLH transcription factors, thereby preventing their DNA binding and suppressing cell differentiation and development. In zebrafish, ID2B is expressed in the endocardium and is crucial for heart valve morphogenesis and cardiac contractility; loss of ID2B results in severe cardiac defects and lethality. ID2B also has roles in sex determination in some fish species, with male-biased expression and conservation/divergence compared to paralogs. In mammals, ID2, not ID2B, is the relevant homolog, and this protein is therapeutically targeted for cancer; homoharringtonine can decrease levels of ID2 protein, providing a basis for potential drug development. The label "ID2B" is misleading for human drug development; the canonical therapeutic target is "Inhibitor of DNA binding 2" (ID2). For most human or mammalian biomedical contexts, "ID2B" is not a valid target; refer instead to "Inhibitor of DNA binding 2 (ID2)." "ID2B" is a species-specific variant/paralog relevant to zebrafish and fish biology, not currently recognized in human gene nomenclature.

Other names

ID2Bid2binhibitor of DNA-binding 2bPutative DNA-binding protein inhibitor ID-2Binhibitor of differentiation 2Bid2bbY

Inhibition of protein synthesis, leading to decreased levels of ID proteins; Blockade of bHLH-directed transcription, suppressing cell differentiation