PSEN1 is integral to the gamma-secretase complex, which is responsible for the intramembrane proteolysis of several type I transmembrane proteins. This includes the cleavage of APP to produce amyloid-beta peptides, a process implicated in Alzheimer's disease. Apart from its role in APP processing, PSEN1 is also involved in the Notch signaling pathway, which is crucial for cell differentiation, proliferation, and apoptosis.
