Proteolytic processing of the hepatocyte growth factor/scatter factor receptor by furin

The hepatocyte growth factor/scatter factor (HGF/SF) receptor consists of an alpha- and a beta-subunit, which are derived from a single-chain precursor by endoproteolytic processing. The precursor is not proteolytically processed in LoVo colon carcinoma cells. The uncleaved receptor immunopurified from the cells was cleaved in vitro by furin. Furthermore, the HGF/SF receptor was proteolytically processed in LoVo cells transfected with furin cDNA. These results indicate that furin is a processing endoprotease for the HGF/SF receptor. Tyrosine autophosphorylation of the uncleaved receptor was induced by HGF/SF, and the growth of the cells expressing the uncleaved receptor was stimulated by HGF/SF, indicating that the proteolytic processing of the receptor is not essential for the signal transduction of HGF/SF.