Function
Serine protease inhibitor that functions in embryonic dorsoventral patterning and the melanization immune response (PubMed:14654000, PubMed:14667416, PubMed:12408809, PubMed:12456640, PubMed:16861233, PubMed:16322759, PubMed:18801354, PubMed:22227521, PubMed:24260243, PubMed:24788090). Regulates dorsoventral axis formation during early development by inhibiting the serine protease easter, and is therefore important for restricting activity of the Toll signaling pathway to the ventral part of the embryo (PubMed:14654000, PubMed:14667416). Also plays an essential role in the melanization immune response to both physical wounding and septic infection using certain bacteria and fungi (PubMed:12408809, PubMed:12456640, PubMed:18801354, PubMed:22227521). Negatively regulates the Hayan-dependent prophenoloxidase 1 (PPO1)-activating cascade in the hemolymph by inhibiting the serine proteases MP1 and Sp7 (PubMed:12408809, PubMed:12456640, PubMed:16861233, PubMed:16322759, PubMed:18801354, PubMed:22227521, PubMed:24260243, PubMed:24788090). May be involved in negatively regulating the melanotic encapsulation around eggs of the parasite L. boulardi (PubMed:12408809, PubMed:15749104).
Sequence
MTKMGGNLAVMLLSLFLSALATGNGNSIPTTTTPQGVFETRTDKLPGGAASVPSGAGIYDDIDTFVPFRSDSHDPFSWHLLKTVLQNETADKNVIISPFSVKLVLALLAEAAGAGTQTQVELANTQTDIRSQNNVREFYRKTLNSFKKENQLHETLSVRTKLFTDSFIETQQKFTATLKHFYDSEVEALDFTNPEAAADAINAWAANITQGRLQQLVAPDNVRSSVMLLTNLIYFNGLWRRQFATTFQGSFFRSKDDQSRAEFMEQTDYFYYTTSEKLKAQILRLPYKGKNSLFVLLPYALNGIHDLVKNLENDELKSAQWAMEEVKVKVTLPKFHFDYQQNLKETLRSLGVREIFEDSASLPGLTRGADVAGKVKVSNILQKAGINVNEKGTEAYAATVVEIENKFGGSTAIEEFNVNRPFVFFIEEESTGNILFAGKVHSPTTQN