Probable subunit of the gamma-secretase complex, an endoprotease complex that catalyzes the intramembrane cleavage of integral membrane proteins such as Notch. Probable component of the gamma-secretase complex, a complex composed of a presenilin homodimer, nicastrin, APH1 and PEN2. A number of isoforms are produced. According to EST sequences. Belongs to the nicastrin family. Was originally thought to correspond to two different genes At3g52640 and At3g52650. Was originally thought to correspond to two different genes At3g52640 and At3g52650.