Abl-interactor (Abi) proteins are targets of Abl-family nonreceptor tyrosine kinases and are required for cytoskeletal reorganization []. Abi1 and Abi2 play an important role in actin cytoskeleton dynamics through participation in several multiprotein complexes. They participate in the formation of the Abi/WAVE complex, which regulates Arp2/3-mediated actin filament nucleation and actin network assembly [, , ].Abi2 is a component of the WAVE1 complex. It localises to sites of actin polymerisation at the tips of lamellipodia and filopodia []. Its structure has been solved [].
This entry represents the ABI family, which includes Abi1, Abi2 and Abi3. They are SH3 domain-containing proteins that are involved in regulation of actin organisation. Abi1, Abi2 and Abi3 all participate in the formation of the Abi/WAVE complex, which regulates Arp2/3-mediated actin filament nucleation and actin network assembly [, , ]. This entry also include Abl interactor homologue (abiA) from Dictyostelium discoideum (Slime mold). abiA is part of a Scar/WAVE complex that is required for proper cytokinesis [].
Abi2 is a component of the WAVE1 complex. It localises to sites of actin polymerisation at the tips of lamellipodia and filopodia []. Mice deficient with Abi2 show defects in orientation and migration of lens fibres, neuronal migration, dendritic spine morphology, as well as deficiencies in learning and memory []. Abi proteins are adaptor proteins serving as binding partners and substrates of Abl tyrosine kinases. They are involved in regulating actin cytoskeletal reorganization and play important roles in membrane-ruffling, endocytosis, cell motility, and cell migration. Abi proteins contain a homeobox homology domain, a proline-rich region, and a SH3 domain []. The SH3 domain of Abi binds to a PxxP motif in Abl [].This entry represents the SH3 domain of Abi2.
Abl-interactor (Abi) proteins are targets of Abl-family nonreceptor tyrosine kinases and are required for cytoskeletal reorganization []. Abi1 and Abi2 play an important role in actin cytoskeleton dynamics through participation in several multiprotein complexes. They participate in the formation of the Abi/WAVE complex, which regulates Arp2/3-mediated actin filament nucleation and actin network assembly [, , ].Abi1 promotes tyrosine phosphorylation of mammalian enabled (Mena) by c-Abl kinase []. It is essential for WAVE2 complex integrity and embryonic survival in mice []. Abi1 and the p85 regulatory subunit of PI-3 kinase may be the link between actin cytoskeleton remodelling and growth receptor signalling [].
