Synectin, syndecan-4 cytoplasmic domain binding PDZ protein, inhibits cellmigration

Syndecan-4, a member of the syndecan gene family of proteoglycans, is an im portant regulator of bFGF signaling. In particular, bFGF-dependent regulati on of cell growth and migration has been linked to syndccan-4 cytoplasmic d omain-mediated interactions. Screening of a yeast two-hybrid library with a cytoplasmic domain of rat syndccan-4 identified a novel binding partner, h ere termed synectin. Synectin is highly homologous to semaphorin F binding protein semcap1, glucose 1 transporter binding protein glut1 cbp, and RGS-G AIP/neuropilin-1 binding protein GIPC. Overexpression of synectin in ECV304 cells in culture led to a dose-dependent inhibition of migration while not affecting cell adhesion or growth rate. We conclude that synectin is invol ved in syndecan-4-dependent interactions and may play a role in the assembl y of syndecan-4 signaling complex. J. Cell. Physiol. 184:373-379, 2000. (C) 2000 Wiley-Liss, Inc.