Probable serine endoprotease which cleaves preproteins at paired basic amino acids (PubMed:16945111). May process FMRFamide-like (flp) and neuropeptide-like protein (nlp) neuropeptides (PubMed:16945111). In muscles, involved in neuronal retrograde signaling by regulating presynaptic activity and localization of synaptic vesicle fusion protein unc-13 at the neuromuscular junction (NMJ) (PubMed:11804572). Acts in the intestine to regulate anterior body muscle contractions (aBOC) and the expulsion steps during the defecation motor program (DMP) (PubMed:2323555, PubMed:11804572, PubMed:18852466, PubMed:25849533). Probably by regulating DMP, required for fatty acid uptake by intestinal cells and therefore regulates the levels of triglycerides in the intestine (PubMed:25849533). Plays a role in locomotion (PubMed:11804572). RNAi-mediated knockdown causes a reduction in fatty acid uptake (PubMed:25849533). RNAi-mediated knockdown in the intestine causes a severe defect in the expulsion step of the defecation cycle (PubMed:18852466). Belongs to the peptidase S8 family. Furin subfamily.