PROPROTEIN CLEAVAGE OF E-CADHERIN BY FURIN IN BACULOVIRUS OVER-EXPRESSION SYSTEM - POTENTIAL ROLE OF OTHER CONVERTASES IN MAMMALIAN-CELLS

Sequence analysis of the adhesion molecule E-cadherin had revealed a m ultibasic motif [(4P)Arg-Gln-Lys-Arg(1P)], reminiscent of the minimal cleavage signal for furin, the prototype of the proprotein convertase family, and/or other members sharing similar sequence specificity. Mut ation of this site was sufficient to abolish processing of E-cadherin in fibroblasts reinforcing the possibility that proprotein convertases are involved in the maturation of this adhesion molecule. Here me dem onstrate that even though furin can efficiently and specifically cleav e proE-cadherin in a baculovirus-based co-expression system, the furin -deficient LoVo cells were found to process endogenous E-cadherin as e fficiently as normal cell Lines. This suggests, for the first time, th at E-cadherin is not only a substrate for furin but for other mammalia n convertases sharing similar sequence specificity. (C) 1998 Federatio n of European Biochemical Societies.