FIG. 9.

Model for the role of ARAP2 in InlB-mediated entry of Listeria. ARAP2 promotes bacterial internalization through at least two distinct pathways. One pathway involves the inactivation of host GTPase Arf6 through the ArfGAP domain in ARAP2. The other pathway involves the RhoA binding domain (RB) of ARAP2, which likely mediates uptake of Listeria by interacting with an unidentified host ligand (X). The ArfGAP activity in ARAP2 is stimulated by binding of the type IA PI 3-kinase product PI(3,4,5)P₃ (PIP3) to PH domains in ARAP2 (42). Based on these data, ARAP2 is one of the likely downstream targets of PI 3-kinase promoting Listeria entry.