Presenilin protein (PSEN1; PSEN2), a potential catalytic subunit of the gamma secretase complex, is an endonuclease complex that catalyzes intramembrane cleavage of integrated membrane proteins such as Notch receptors and APP (beta - amyloid precursor protein). May play a role in intracellular signal transduction and gene expression, or in connecting chromatin and nuclear membrane. Patients with hereditary Alzheimer's disease (AD) carry mutations in presenilin protein or amyloid precursor protein (APP). These disease-related mutations lead to an increase in the production of longer forms of beta amyloid protein (the main component of amyloid deposits found in AD brains).
