ADAM12-mediated focal adhesion formation is differently regulated by β1 and β3 integrins

ADAM12, adisintegrin and metalloprotease, has been demonstrated to be upregulated in human malignant tumors and to accelerate the malignant phenotype in a mouse model for breast cancer. ADAM12 is a substrate for β1 integrins and may affect tumor and stromal cell behavior through its binding to β1 integrins. Here, we report that cells deficient in β1 integrin or overexpressing β3 integrin can bind to recombinant full-length human ADAM12 via β3 integrin. Furthermore, cell binding to ADAM12 via β3 integrin results in the formation of focal adhesions, which are not formed upon β1 integrin-mediated cell attachment. We also show that RhoA is involved in β3 integrin-mediated focal adhesion formation.