Endopeptidase (By similarity). Plays a key role in innate immunity by activating the Toll pathway in response to fungal and Gram-positive bacterial infections, presumably downstream of pattern-recognition receptors (PRR), such as PGRP-SA, GNBP1 and GNBP3, and upstream of spz processing enzyme SPE (PubMed:16631589, PubMed:18724373). Probably secreted in the hemolymph. The clip domain consists of 35-55 residues which are 'knitted' together usually by 3 conserved disulfide bonds forming a clip-like compact structure. Proteolytically cleaved by a tryspin-like protease which is likely to activate grass. Results in increased susceptibility to fungal or Gram-positive bacterial infection and failure to induce the expression of the Toll pathway-activated antifungal peptide Drs (PubMed:18724373). siRNA-mediated knockdown results in increased susceptibility to Gram-positive bacterial infection and severe reduction in the expression of the antifungal peptide Drs (PubMed:16631589). In a protease psh mutant background, complete loss of Drs induction and increased susceptibility to Gram-positive bacterial infection (PubMed:18724373). Belongs to the peptidase S1 family. CLIP subfamily. Extended N-terminus.