The P2Y2 nucleotide receptor requires interaction with αv integrins to access and activate G12

The P2Y(2) nucleotide receptor (P2Y(2)R) interacts with alpha nu integrins to activate G(o) and induce chemotaxis in human 1321N1 astrocytoma cells. In this study, it was determined that the P2Y(2)R also requires interaction with alpha nu integrins to activate G(12) and associated signaling pathways that control chemotaxis in 1321N1 cells. Mutation of the Arg-Gly-Asp (RGD) integrin-binding sequence in the first extracellular loop of the human P2Y(2)R to Arg-Gly-Glu (RGE), which prevents integrin interaction, did not inhibit G(q) or ERK1/2 signaling by the P2Y(2)R agonist UTP but completely inhibited activation of G(12) and G(12)-mediated events, including Rho activation, cofilin and myosin light chain-2 phosphorylation, stress fiber formation and chemotaxis towards UTP. The involvement of G(12) in all these events was verified by using a dominant negative G alpha(12) construct. G(12) activation by the P2Y(2)R also was inhibited by anti-alpha nu beta 5 integrin antibodies and alpha nu integrin antisense oligonucleotides, suggesting that alpha nu integrin activity and expression are required for the P2Y(2)R to activate G(12). Co-immunoprecipitation experiments confirmed that G alpha(12) protein associates with the wild-type P2Y(2)R and with alpha nu integrins but not with the RGE mutant P2Y(2)R or with alpha 3 integrins. Collectively, these results suggest that alpha nu integrin complexes provide the P2Y(2)R with access to G(12), thereby allowing activation of this heterotrimeric G protein that controls actin cytoskeletal rearrangements required for chemotaxis.