Brain-specific angiogenesis inhibitor 1-associated protein 2 (BAIAP2)

Brain-specific angiogenesis inhibitor 1-associated protein 2 (BAIAP2), also known as IRSp53, is a multifunctional adaptor protein that acts as a central integrator of membrane curvature, actin cytoskeleton remodeling, and Rho-family GTPase signaling[1][4]. It contains a conserved N-terminal IMD (IRSp53/MIM homology) domain that binds and deforms cellular membranes, facilitating the formation of filopodia and lamellipodia in motile cells[1]. The C-terminal SH3 domain enables recruitment of actin regulatory proteins (such as Mena, Eps8, WASF family, and Arp2/3 complex), allowing BAIAP2 to spatially and temporally regulate actin assembly in coordination with Rac1 and Cdc42 pathways[1][4]. BAIAP2 is pivotal for cell migration, invasion, and neuronal morphogenesis, with critical roles in growth cone guidance, synaptic structure, and developmental patterning. Disease associations include its fusion with FGFR3 in some bladder cancers generating oncogenic signals, and its interaction with the DRPLA gene implicated in autosomal dominant neurodegenerative disorders[1][4]. It is also exploited by certain pathogens to modulate host cytoskeletal architecture[1]. The dynamic coordination of membrane deformation and actin remodeling by BAIAP2/IRSp53 underscores its importance in both physiological and pathological cellular processes.

Other names

IRSp53IRS-58BAI-associated protein 2BAP2Fas ligand-associated factor 3 (FLAF3)WASP and MIM like (WAML)Insulin receptor substrate p53Insulin receptor substrate p53/p58Insulin receptor substrate protein of 53 kDaInsulin receptor substrate of 53 kDaBAI1-associated protein 2Protein BAP2Brain-specific angiogenesis inhibitor 1-associated protein 2IRSp53/58IRSP53