Predicted to enable endopeptidase activity. Involved in several processes, including apical protein localization; egg-laying behavior; and regulation of signal transduction. Located in perinuclear region of cytoplasm. Used to study Alzheimer's disease. Human ortholog(s) of this gene implicated in several diseases, including Alzheimer's disease 3; Alzheimer's disease 4; Pick's disease; dilated cardiomyopathy (multiple); and hidradenitis suppurativa. Is an ortholog of human PSEN1 (presenilin 1) and PSEN2 (presenilin 2).