module: dmel_er_membrane_protein_complex
title: ER membrane protein complex (EMC) in Drosophila melanogaster
label: ER membrane protein complex
module_type: PROTEIN_COMPLEX
description: >-
  The ER membrane protein complex (EMC) is a multisubunit membrane protein
  insertase in the endoplasmic reticulum. It inserts tail-anchored proteins
  with moderately hydrophobic transmembrane segments and the first
  transmembrane segment of many multipass membrane proteins in the N-terminus
  out orientation, and it supports biogenesis of other multipass proteins. The
  conserved hydrophilic vestibule formed by EMC3 and EMC6 in the membrane
  carries out insertion, while the cytosolic EMC2 and EMC8/9 and the large
  lumenal EMC1, EMC7 and EMC10 subunits shape the complex. In Drosophila the
  EMC is required in photoreceptors for the biogenesis of rhodopsin and other
  multipass membrane proteins. Drosophila has two EMC2 paralogs, EMC2A and
  EMC2B, which FlyBase treats as alternative subunits.
summary: >-
  Multisubunit ER membrane insertase for tail-anchored and multipass membrane
  proteins, with EMC2A or EMC2B variants.
concepts:
  - {id: GO:0072546, label: EMC complex}
cellular_components:
  - {id: GO:0005789, label: endoplasmic reticulum membrane}
notes: >-
  Decomposition. The subunits shared by both FlyBase variants form one part;
  EMC2A and EMC2B are alternatives. The insertase activity is assigned to
  EMC3, the core subunit of the insertion vestibule; EMC6 contributes to the
  same site.
parts:
  - id: emc_shared_subunits
    label: Shared EMC subunits
    role: insertase core and structural subunits
    genes: [EMC1, EMC3, EMC4, EMC5, EMC6, EMC7, EMC8-9, EMC10]
    unit_functions:
      EMC3: {id: GO:0032977, label: membrane insertase activity}
    processes:
      - {id: GO:0071816, label: tail-anchored membrane protein insertion into ER membrane}
  - id: emc2_subunit
    label: EMC2 subunit
    role: cytosolic EMC2 subunit
    variant_sets:
      - id: emc2_variants
        label: EMC2A or EMC2B
        selection: ONE_OR_MORE
        variants:
          - {id: emc2a, label: EMC2A, genes: [EMC2A], complex: false}
          - {id: emc2b, label: EMC2B, genes: [EMC2B], complex: false}