ID1 Recombinant Rabbit mAb (S-4053-142)

ID1 (Inhibitor of DNA binding 1, also known as inhibitor of differentiation 1) is a nuclear transcriptional regulatory protein of approximately 154 amino acids (molecular weight ~16 kDa) encoded by the ID1 gene on human chromosome 20, and a member of the dominant-negative helix-loop-helix (dnHLH) family. Its core functional mechanism lies in the fact that ID1 contains an HLH dimerization domain but lacks a basic DNA-binding domain, and can therefore form heterodimers with basic HLH (bHLH) transcription factors, sequestering them in an inactive state incapable of binding DNA and thereby negatively regulating the transcriptional activation activity of bHLH transcription factors. Through this mechanism, ID1 is broadly involved in the regulation of cell growth, senescence, differentiation, apoptosis, angiogenesis, and tumor transformation, and regulates cell proliferation and differentiation in myogenesis, neurogenesis, and hematopoiesis. At the physiological level, ID1 also participates in regulating the circadian clock (by inhibiting the transcriptional activation activity of the CLOCK–BMAL1 heterodimer) and in VEGFR2–ID1-mediated release of angiocrine factors during liver regeneration. In tumors, ID1 is generally regarded as a pro-oncogenic factor, being overexpressed in various malignant tumors such as thyroid cancer, glioma, and lung cancer, and promoting tumor cell proliferation, migration, and angiogenesis.