Screening cellular proteins involved in the anti-proliferative effect of the ADAM15 disintegrin domain in murine melanoma cells

A disintegrin and metalloprotease protein 15 (ADAM15), a membrane-anchored glycoprotein, is believed to function in cell-cell interactions via an integrin binding motif within its disintegrin domain. To screen its target proteins, the recombinant ADAM15 disintegrin domain (RADD) was expressed in Escherichia coli, biotinylated and used in a protein pull-down assay in vitro. A total of eight kinds of proteins were identified by 2DE/LC-MS-MS. One of them, p38 kinase, was selected for further investigation of its involvement in the anti-proliferative effect of RADD on melanoma cells. Phosphorylation of p38 kinase in melanoma cells was detected upon treatment with RADD. Furthermore, the suppression of p38 kinase activity resulted in a decrease in the RADD inhibitory effect on melanoma cell proliferation. These results provide evidence that RADD inhibits melanoma cell proliferation partly through p38 kinase activation.