Inhibitor of DNA binding 1 (ID1) (ID1)

Inhibitor of DNA binding 1 (ID1) is a member of the inhibitor of differentiation family of helix-loop-helix (HLH) proteins that acts as a key regulator of cell fate and proliferation (UniProt: P41128). Unlike basic HLH (bHLH) transcription factors, ID1 lacks a DNA-binding domain, functioning instead as a dominant-negative antagonist by heterodimerizing with bHLH proteins, such as E-proteins, to prevent them from binding to DNA and initiating differentiation (PubMed: 25103445). This molecular mechanism maintains cells in an undifferentiated, proliferative state, which is essential during development but often co-opted in disease. In oncology, ID1 is frequently overexpressed and serves as a driver of tumor progression, epithelial-mesenchymal transition (EMT), and metastasis across various cancers, including breast, lung, and glioblastoma (PubMed: 30104358). Therapeutic strategies targeting ID1 signaling focus on small molecule inhibitors like AGX51 that disrupt its protein-protein interactions or agents like cannabidiol that downregulate its expression (PubMed: 31434016, PubMed: 21907120). However, the lack of a traditional ligand-binding pocket makes ID1 a challenging target, requiring innovative approaches to modulate its activity or stability.

Other names

Inhibitor of differentiation 1IDbHLHb24Helix-loop-helix protein id1Class B basic helix-loop-helix protein 24

Disruption of ID1 protein-protein interactions with bHLH transcription factors or downregulation of ID1 gene expression to restore cell differentiation pathways.