P2Y 2 receptors induced cell surface redistribution of α v integrin is required for activation of ERK 1/2 in U937 cells

Nucleotides released from cells due to stress, injury or inflammation, induce mitogenic effects in monocytes via activation of P2Y 2 nucleotide receptors (P2Y 2 Rs). Here we show that P2Y 2 nucleotide receptors in U937 monocytic cells regulate the activation of extracellular signal‐regulated kinases 1 and 2 (ERK 1/2) by inducing the clustering of α v integrins. The activation of phosphatidylinositol 3‐kinase by P2Y 2 R ligands was required for α v clustering, suggesting a means whereby two different classes of receptors communicate to induce mitogenic responses in monocytic cells. P2Y 2 R‐induced α v clustering was also associated with a flattened phenotype of the U937 cells, consistent with the role of the P2Y 2 R in regulating early events in cell migration. J. Cell. Physiol. 211: 410–422, 2007. © 2006 Wiley‐Liss, Inc.