module: dmel_gamma_secretase_complex
title: Gamma-secretase complex in Drosophila melanogaster
label: Gamma-secretase complex
module_type: PROTEIN_COMPLEX
description: >-
  Gamma-secretase is an intramembrane aspartyl protease that cleaves
  type I membrane proteins within their transmembrane domains after their
  ectodomains have been shed. Presenilin (Psn) is the catalytic subunit and
  carries the two catalytic aspartates; nicastrin (Nct), Aph-1 and Pen-2 are
  required for assembly, maturation and activity. In Drosophila the complex
  performs the S3 cleavage of Notch that releases the Notch intracellular
  domain, so loss of its subunits causes Notch-like phenotypes.
summary: >-
  Four-subunit intramembrane aspartyl protease (Psn, Nct, aph-1, pen-2) that
  releases the Notch intracellular domain.
concepts:
  - {id: GO:0070765, label: gamma-secretase complex}
parts:
  - id: catalytic_subunit
    label: Presenilin
    role: catalytic subunit
    genes: [Psn]
    function: {id: GO:0004190, label: aspartic-type endopeptidase activity}
  - id: accessory_subunits
    label: Nicastrin, Aph-1 and Pen-2
    role: assembly and substrate-recognition subunits
    genes: [Nct, aph-1, pen-2]
notes: >-
  Presenilin autoproteolysis into N- and C-terminal fragments, promoted by
  Pen-2, is part of complex maturation. Gamma-secretase substrates other than
  Notch are not modelled.