Bi-cycling the furin pathway: from TGN localization to pathogen activationand embryogenesis

Furin is a secretory Pathway endoprotease that catalyses the maturation of a strikingly diverse group of proprotein substrates, ranging from growth fa ctors and receptors to pathogen proteins, In multiple compartments within t he trans-Golgi network (TGN)/endosomal system. This review focuses on recen t developments in the biochemistry and cell biology of the endoprotease, in cluding the mechanism of TGN localization, phosphorylation-dependent regula tion of protein traffic, and novel insights into, early embryogenesis, extr acellular matrix formation and pathogen virulence.