Manduca sexta serpin-5 regulates prophenoloxidase activation and the Toll signaling pathway by inhibiting hemolymph proteinase HP6.

ABSTRACT: Insect immune responses include prophenoloxidase (proPO) activation and Toll pathway initiation, which are mediated by serine proteinase cascades and regulated by serpins. Manduca sexta hemolymph proteinase-6 (HP6) is a component of both pathways. It cleaves and activates proPO activating proteinase 1 (PAP1) and hemolymph proteinase-8 (HP8), which activates proSpätzle. Inhibitors of HP6 could have the capability of regulating both of these innate immune proteinase cascade pathways. Covalent complexes of HP6 with serpin-4 and serpin-5 were previously isolated from M. sexta plasma using immunoaffinity chromatography with serpin antibodies. We investigated the inhibition of purified, recombinant HP6 by serpin-4 and serpin-5. Both serpin-4 and serpin-5 formed SDS-stable complexes with HP6 in v

SUBMITTER: An C 

PROVIDER: S-EPMC2933306 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature