PSEN 2

Role in the organism:

Presenilin 2 is part of a large protein complex known as gamma secretase, whose function is to prevent fragmentation of other proteins and protein complexes. One of the proteins produced by this pathway is the amyloid precursor protein (APP).

Role in the disorder (state):

Certain mutations in the PSEN2 locus are associated with Alzheimer's disease, which involves the accumulation of a large amount of APP (known as beta-amyloid protein) in the brain. Such mutations obviously increase gamma secretase activity. Alzheimer's disease can result in mutations in the gene encoding the protein presenilin 1, which is also part of the gamma secretase complex (see PSEN1 gene on chromosome 14) and mutations in the APP gene (on chromosome 21).