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Aph-1 protein This family consists of several eukaryotic Aph-1 proteins.Gamma-secretase catalyzes the intramembrane proteolysis of Notch, beta-amyloid precursor protein, and other substrates as part of a new signaling paradigm and as a key step in the pathogenesis of Alzheimer's disease. It is thought that the presenilin heterodimer comprises the catalytic site and that a highly glycosylated form of nicastrin associates with it. Aph-1 and Pen-2, two membrane proteins genetically linked to gamma-secretase, associate directly with presenilin and nicastrin in the active protease complex. Co-expression of all four proteins leads to marked increases in presenilin heterodimers, full glycosylation of nicastrin, and enhanced gamma-secretase activity. APH-1 proteins have a similar but different set of motifs as compared to other families. Their four motifs are: QExxR, Fxxxx, Hxxxs and Hxxxs respectively. Given the inferred homology between APH-1 and other membrane proteases such as type II CAAX proteases and PrsW proteases, it is speculated that APH-1 may possess protease activity. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",