Furin-mediated protein processing in infectious diseases and cancer

Braun, Elisabeth; Sauter, Daniel

Furin is a member of the evolutionarily ancient family of proprotein convertases. Their similarity with bacterial subtilisin and yeast kexin proteases has coined the abbreviation PCSK (proprotein convertase subtilisin/kexin type). Humans encode nine members of this protease family (PCSK1-9), with PCSK3 representing furin (Table 1) . PCSKs are well known for their ability to activate other cellular proteins. The proteolytic conversion of inactive precursor proteins into bioactive molecules has already been described in the 1960s. 3 However, it took more than 20 years until furin was identified as the first mammalian proprotein convertase. 4, 5 To date, more than 200 cellular substrates of PCSKs have been described, including hormones, receptors, growth factors and adhesion molecules.