Interaction of integrin α6β4 with ErbB3 and implication in heregulin-induced ErbB3/ErbB2-mediated DNA synthesis

Abstract

Integrin α6β4 is abundantly expressed in normal epithelial cells and forms hemidesmosomes, one of cell-extracellular matrix junctions. In many types of cancer cells, integrin α6β4 is up-regulated, laminin, an integrin α6β4-binding extracellular matrix protein, is cleaved, and hemidesmosomes are disrupted, eventually causing an enhancement of cancer cell movement and a facilitation of their invasion. It was previously shown that integrin α6β4 interacts with ErbB1 and ErbB2 and enhances cell proliferation and motility. Here we show that integrin α6β4 interacts with ErbB3 but not with ErbB1, ErbB2 or ErbB4, and enhances the heregulin-induced, ErbB3/ErbB2 heterodimer-mediated DNA synthesis, but not cell motility, in A549 cells. © 2010 The Authors. Journal compilation © 2010 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.