A possible role of vimentin on the cell surface for the activation of latent transforming growth factor-β

Latent TGF-beta (LTGF-beta) has to be converted to active TGF-beta for its activities. Previously, we reported that certain fragments of latency associated peptide (LAP) augmented LTGF-beta activation via increase in binding of LTGF-beta to the endothelial cell (EC) surface followed by cell-associated proteolysis. By searching for EC membrane proteins crosslinked with the LAP fragment, we identified the molecule bound to LAP fragment as vimentin. Moreover, the LAP fragment-induced LTGF-beta activation was attenuated by anti-vimentin antibody. These results indicate that binding of the LAP fragment to vimentin on the cell surface is indispensable for LTGF-beta activation by the LAP fragment.