RNA recognition motif 1 (RRM1) found in vertebrate insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2)
This subgroup corresponds to the RRM1 of IGF2BP2 (IGF2 mRNA-binding protein 2 or IMP-2), also termed hepatocellular carcinoma autoantigen p62, or VICKZ family member 2, which is a ubiquitously expressed RNA-binding protein involved in the stimulation of insulin action. It is predominantly nuclear. SNPs in IGF2BP2 gene are implicated in susceptibility to type 2 diabetes. IGF2BP2 plays an important role in cellular motility; it regulates the expression of PINCH-2, an important mediator of cell adhesion and motility, and MURF-3, a microtubule-stabilizing protein, through direct binding to their mRNAs. IGF2BP2 may be involved in the regulation of mRNA stability through the interaction with the AU-rich element-binding factor AUF1. IGF2BP2 binds initially to nascent beta-actin transcripts and facilitates the subsequent binding of the shuttling IGF2BP1. IGF2BP2 contains four hnRNP K-homology (KH) domains, two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a RGG RNA-binding domain.