Non-catalytic subunit of the gamma-secretase complex, an endoprotease complex that catalyzes the intramembrane cleavage of integral membrane proteins such as Notch receptors and APP (amyloid- beta precursor protein) (PubMed:12297508, PubMed:12522139, PubMed:12679784, PubMed:12763021, PubMed:25043039, PubMed:26280335, PubMed:30598546, PubMed:30630874). Required for normal gamma-secretase assembly (PubMed:12471034, PubMed:12522139, PubMed:12763021, PubMed:19369254). The gamma-secretase complex plays a role in Notch and Wnt signaling cascades and regulation of downstream processes via its role in processing key regulatory proteins, and by regulating cytosolic CTNNB1 levels (Probable). {ECO:0000269|PubMed:12297508, ECO:0000269|PubMed:12471034, ECO:0000269|PubMed:12522139, ECO:0000269|PubMed:12679784, ECO:0000269|PubMed:12763021, ECO:0000269|PubMed:25043039, ECO:0000269|PubMed:26280335, ECO:0000269|PubMed:30598546, ECO:0000269|PubMed:30630874, ECO:0000305}. This is the function of ENSG00000117362 (APH1A, aph-1A gamma-secretase subunit).