PSEN 1

Role in the organism:

Presenilin 1 acts as part of a large protein complex called gamma secretase, whose function is to cleave other proteins into smaller segments. One of the proteins affected by this complex is the amyloid precursor protein (APP).

Role in the disorder (state):

Certain mutations in the PSEN1 gene have been linked to Alzheimer's disease, a neurodegenerative disease that involves the accumulation of large amounts of the processed form of APP in the brain, known as the beta-amyloid protein. This produces characteristic lesions composed of dead and fragmented brain cells surrounded by amyloid plaques. Mutations in the PSEN1 gene can cause beta-amyloid protein accumulation by enhancing or modifying gamma secretase activity. Alzheimer's disease may be the result of mutations in the PSEN2 gene on chromosome 1, which encodes presenilin 2 (another component of the gamma secretase complex) and may also be caused by mutations in the APP gene located on chromosome 21.