Abl interactor 1 also known as Abelson interactor 1 (Abi-1) is a protein that in humans is encoded by the ABI1 gene. The protein encoded by this gene has been found to form a complex with EPS8 and SOS1, and is thought to be involved in the transduction of signals from Ras to Rac. In addition, the encoded protein may play a role in the regulation of EGF-induced Erk pathway activation as well as cytoskeletal reorganization and EGFR signaling. Several transcript variants encoding multiple isoforms have been found for this gene. [provided by RefSeq].
May act in negative regulation of cell growth and transformation by interacting with nonreceptor tyrosine kinases ABL1 and/or ABL2. May play a role in regulation of EGF-induced Erk pathway activation. Involved in cytoskeletal reorganization and EGFR signaling. Together with EPS8 participates in transduction of signals from Ras to Rac. In vitro, a trimeric complex of ABI1, EPS8 and SOS1 exhibits Rac specific guanine nucleotide exchange factor (GEF) activity and ABI1 seems to act as an adapter in the complex. Regulates ABL1/c-Abl-mediated phosphorylation of ENAH. Recruits WASF1 to lamellipodia and there seems to regulate WASF1 protein level (By similarity).