ID1 (F2M1J) Rabbit mAb (IF/Flow Formulated) #25344

Inhibitor of DNA-binding/Differentiation (ID) proteins are a family of proteins that function to repress the activity of basic helix-loop-helix (bHLH) transcription factors. There are four known ID proteins in humans (ID1-4), all of which contain a helix-loop-helix domain but lack a basic DNA-binding domain. Heterodimerization with bHLH transcription factors, therefore, functions to sequester bHLH proteins and prevent their binding to DNA (1). ID proteins play important functional roles in development, primarily by inhibiting premature differentiation of stem/progenitor cells (1,2). ID1 plays important regulatory roles downstream of TGF-β and BMP signaling by inhibiting various transcription factors (3,4). SMAD3 is capable of binding to the ID1 promoter, causing upregulation in response to TGF-β (5). High expression of ID1 is associated with increased cancer growth and migration by inhibiting cell cycle regulators p16, p21, and p27 (6,7). ID1 as a therapeutic target is context dependent. While high expression of ID1 is generally associated with poor prognosis, drug sensitivity can vary greatly depending on tumor type (8-10).