brain-specific angiogenesis inhibitor 1-associated protein 2 (BAI1-associated protein 2, protein BAP2, insulin receptor substrate p53, IRSp53, insulin receptor substrate protein of 53 kD, insulin receptor substrate p53/p58, IRSp53/58, IRS-58, Fas ligand-associated factor 3, FLAF3, BAIAP2)

Function

• adapter protein
• links membrane-bound small G-proteins to cytoplasmic effector proteins
• CDC42-mediated reorganization of actin cytoskeleton
• RAC1-mediated membrane ruffling
• regulation of actin cytoskeleton by WASF family members & Arp2/3 complex
• neurite growth
• acts syngeristically with ENAH to promote filipodia formation.
• homodimer
• interacts with CDC42 & RAC1 activated by GTP binding
• interacts with ATN1, BAI1, EPS8, SHANK1, SHANK2, SHANK3, WASF1, WASF2
• interacts with ENAH after recruitment of CDC42
• interacts with TIAM1, DIAPH1
• IMD domain forms a coiled coil
  • the isolated domain can induce actin bundling & filopodia formation
• in the absence of G-proteins, intramolecular interaction between the IMD & theSH3 domain gives rise to an auto- inhibited state
• interaction of the IMD with RAC1 or CDC42 leads to activation.
• SH3 domain interacts with ATN1, BAI1, WASF1, WASF2, SHANK1, DIAPH1, ENAH
• phosphorylated on TYR by INSR in response to insulin

Compartment

• cytoplasm, peripheral membrane
• detected in filopodia & close to membrane ruffles

Alternative splicing

named isoforms=6

Expression

• isoform 1 & isoform 4 are expressed almost exclusively in brain

More general terms

• phosphoprotein

Additional terms

• brain-specific angiogenesis inhibitor 1

Database

• OMIM: https://mirror.omim.org/entry/605475
• UniProt: http://www.uniprot.org/uniprot/Q9UQB8.html