Collagenous lectins in tunicates and the proteolytic activation of complement.

Abstract

Complement activation in vertebrates has traditionally been associated with the classical (antibody mediated) or alternative (spontaneously hydrolytic) pathways. Recently, a new mechanism of complement activation has been identified in which a collagenous lectin (collectin), mannose binding protein (MBP) and its associated serine protease (MASP) activate the central component of the complement system, C3 (Epstein, et al., 1996, Holmskov, et al., 1994, Hoppe and Reid, 1994, Lu, 1997). Two components of this lectin-mediated complement pathway have already been identified in invertebrates. Echinoderms express a C3 homologue and a number of other complement components, whilst a MASP-like serine protease and a C3 homologue have been identified in tunicates (Al-Sharif, et al., 1998, Azumi, et al., 1993, Nonaka, et al., 1998, Smith, et al., 1996, Smith, et al., 1998).KeywordsComplement ComponentCarbohydrate BindingOpsonic ActivityHigh Order OligomerAmino Acid Composition AnalysisThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.