ABI2
Domain
The SH3 domain is critical for binding to ABL1 and ABL2.
Function
Regulator of actin cytoskeleton dynamics underlying cell motility and adhesion. Functions as a component of the WAVE complex, which activates actin nucleating machinery Arp2/3 to drive lamellipodia formation (PubMed:21107423). Acts as a regulator and substrate of nonreceptor tyrosine kinases ABL1 and ABL2 involved in processes linked to cell growth and differentiation. Positively regulates ABL1-mediated phosphorylation of ENAH, which is required for proper polymerization of nucleated actin filaments at the leading edge (PubMed:10498863, PubMed:7590236, PubMed:8649853). Contributes to the regulation of actin assembly at the tips of neuron projections. In particular, controls dendritic spine morphogenesis and may promote dendritic spine specification toward large mushroom-type spines known as repositories of memory in the brain (By similarity). In hippocampal neurons, may mediate actin-dependent BDNF-NTRK2 early endocytic trafficking that triggers dendrite outgrowth (By similarity). Participates in ocular lens morphogenesis, likely by regulating lamellipodia-driven adherens junction formation at the epithelial cell-secondary lens fiber interface (By similarity). Also required for nascent adherens junction assembly in epithelial cells (PubMed:15572692).
Involvement in disease
There is evidence, including phenotypic data from ABI2-knockout mice, that loss-of-function variants in ABI2 may play a role in autosomal recessive intellectual disability.
Post-translational modifications
Phosphorylated by ABL1.
Sequence Similarities
Belongs to the ABI family.
Tissue Specificity
Widely expressed. Abundant in testes, ovary, thymus, and colon, with lower but detectable levels in prostate, peripheral blood leukocytes, and spleen.
Cellular localization
- Cytoplasm
- Nucleus
- Isoform 1
- Cell projection
- Lamellipodium
- Cell projection
- Filopodium
- Cytoplasm
- Cytoskeleton
- Cell junction
- Adherens junction
- Isoform 1 but not isoform 3 is localized to protruding lamellipodia and filopodia tips (PubMed:11516653, PubMed:15572692). Present at nascent adherens junctions, where it clusters adjacent to the tips of F-actin protrusions (PubMed:15572692).
Alternative names
ARGBPIA, ABI2, Abl interactor 2, Abelson interactor 2, Abl-binding protein 3, Arg-binding protein 1, Abi-2, AblBP3, ArgBP1