Abstract
Integrins are heterodimeric transmembrane receptors that physically link the extracellular matrix (ECM) to the intracellular actin cytoskeleton, and are also signaling molecules that transduce signals bi-directionally across the plasma membrane. Integrin regulation is essential for tumor cell migration in response to growth factors. c-Abl kinase is a nonreceptor tyrosine kinase and is critical for signaling transduction from various receptors. Here we show that c-Abl kinase is involved in A375 cell migration mediated by αvβ3 integrin in response to PDGF stimulation. c-Abl kinase colocalizes with αvβ3 integrin dynamically and affects αvβ3 integrin affinity by regulating its cluster. The interaction between c-Abl kinase and αvβ3 integrin was dependent on the activity of c-Abl kinase induced by PDGF stimulation, but was not dependent on the binding of αvβ3 integrin with its ligands, suggesting that c-Abl kinase is not involved in the outside-in signaling of αvβ3 integrin. Talin head domain was required for the interaction between c-Abl kinase and αvβ3 integrin, and the SH3 domain of c-Abl kinase was involved in its interaction with talin and αvβ3 integrin. Taken together, we have uncovered a novel and critical role of c-Abl kinase in αvβ3 integrin mediated melanoma cell migration.