Nicastrin (abbreviated NCT) is a
protein that is part of the
gamma secretase protein complex, which is one of the
proteases involved in processing
amyloid precursor protein (APP) to the short
Alzheimer's disease-associated peptide
amyloid beta. The other proteins in the complex are
PSEN1 (presenilin-1), which is the
catalytically active component of the complex,
APH-1 (anterior pharynx-defective 1), and
PEN-2 (presenilin enhancer 2). Nicastrin itself is not catalytically active, but instead promotes the maturation and proper trafficking of the other proteins in the complex, all of which undergo significant
post-translational modification before becoming active in the cell. Nicastrin has also been identified as a regulator of
neprilysin, an
enzyme involved in the degradation of amyloid beta fragment. ==History==