DNA-binding protein inhibitor ID-1 is a protein that in humans is encoded by the ID1 gene. [5] [6]
The protein encoded by this gene is a helix-loop-helix (HLH) protein that can form heterodimers with members of the basic HLH family of transcription factors. [5] The encoded protein has no DNA binding activity and therefore can inhibit the DNA binding and transcriptional activation ability of basic HLH proteins with which it interacts. [5] This protein may play a role in cell growth, senescence, and differentiation. [7] [8] [9] Two transcript variants encoding different isoforms have been found for this gene. [10]
ID1 has been shown to interact weakly with MyoD [5] [11] [12] [13] [14] [15] [16] but very tightly with ubiquitously expressed E proteins. [17] E proteins heterodimerize with tissue restricted bHLH proteins such as Myod, NeuroD, etc. to form active transcription complexes so by sequestering E proteins, Id proteins can inhibit tissue restricted gene expression in multiple cell lineages using the same biochemical mechanism. Other interacting partners include CASK. [18]
ID1 can be used to mark endothelial progenitor cells which are critical to tumor growth and angiogenesis. [19] [20] Targeting ID1 results in decreased tumor growth. [21] [22] ID1 has been shown to be targeted by cannabidiol in certain gliomas and breast cancers. [23] [24]
This article incorporates text from the United States National Library of Medicine, which is in the public domain.