Serine endoprotease that processes various proproteins by cleavage at paired basic amino acids, recognizing the RXXX[KR]R consensus motif. Likely functions in the constitutive and regulated secretory pathways. Plays an essential role in pregnancy establishment by proteolytic activation of a number of important factors such as BMP2, CALD1 and alpha-integrins. Secreted through the regulated secretory pathway. Type I membrane protein localized to a paranuclear post-Golgi network compartment in communication with early endosomes. Expressed in T-lymphocytes. The propeptide domain acts as an intramolecular chaperone assisting the folding of the zymogen within the endoplasmic reticulum. AC 1 and AC 2 (clusters of acidic amino acids) contain sorting information. AC 1 directs TGN localization and interacts with the TGN sorting protein PACS-1 (By similarity). Belongs to the peptidase S8 family.