Minor histocompatibility antigen H13 (HM13)

Catalyzes intramembrane proteolysis of a signal peptides after they have been cleaved from a preprotein, leading to the discharge of the fragment from the ER membrane to the cytoplasm. Required to generate lymphocyte cell surface (HLA-E) epitopes derived from MHC class I signal peptides (PubMed:11714810).

Might be necessary for the elimination of the signal peptide that remains attached to the hepatitis C virus core protein after the initial proteolytic processing of the polyprotein (PubMed:12145199). Involved in the intramembrane cleavage of this integral membrane protein PSEN1 (PubMed:12077416, PubMed:11714810, PubMed:14741365).