module: dmel_sec61_translocon
title: Sec61 translocon and associated complexes in Drosophila melanogaster
label: Sec61 translocon
module_type: PROTEIN_COMPLEX
description: >-
  The Sec61 complex is the protein-conducting channel of the endoplasmic
  reticulum membrane. Its alpha subunit forms an hourglass-shaped pore with a
  lateral gate through which signal sequences and transmembrane segments of
  nascent polypeptides enter the lipid bilayer; the small beta and gamma
  subunits stabilize the channel. Sec61 receives ribosome-nascent chain
  complexes from the SRP receptor for cotranslational translocation, and with
  the Sec62-Sec63 complex it also translocates proteins post-translationally.
  Translocon-associated proteins such as TRAM and the TRAP complex assist the
  insertion and translocation of particular substrates. Drosophila has three
  Sec61 gamma genes, Sec61gamma, CG8860 and the testis-expressed CG13426,
  giving alternative forms of the channel.
summary: >-
  Sec61 protein-conducting channel with its gamma-subunit variants, the
  Sec62-Sec63 post-translational translocation complex and translocon-associated
  proteins.
concepts:
  - {id: GO:0071256, label: translocon complex}
cellular_components:
  - {id: GO:0005789, label: endoplasmic reticulum membrane}
notes: >-
  Decomposition. The Sec61 heterotrimer is modelled as three variants that
  differ in their gamma subunit, following FlyBase. FlyBase groups only TRAM
  and Tapdelta as translocon-associated proteins; they are modelled as
  individual proteins and the other TRAP subunits are not added. SRP targeting
  is the separate module dmel_srp_cotranslational_targeting; signal peptidase
  and oligosaccharyltransferase are outside this module.
parts:
  - id: sec61_channel
    label: Sec61 channel
    role: protein-conducting channel
    variant_sets:
      - id: sec61_gamma_variants
        label: Sec61 complexes with alternative gamma subunits
        selection: ONE_OR_MORE
        variants:
          - id: sec61_sec61gamma
            label: Sec61 complex with Sec61gamma
            group: SEC61T-G2
            complex_term: {id: GO:0005784, label: Sec61 translocon complex}
            unit_functions:
              Sec61alpha: {id: GO:0008320, label: transmembrane protein transporter activity}
            processes:
              - {id: GO:0006616, label: "SRP-dependent cotranslational protein targeting to membrane, translocation"}
          - id: sec61_cg8860
            label: Sec61 complex with CG8860 gamma subunit
            group: SEC61T-CG8860
            complex_term: {id: GO:0005784, label: Sec61 translocon complex}
            unit_functions:
              Sec61alpha: {id: GO:0008320, label: transmembrane protein transporter activity}
            processes:
              - {id: GO:0006616, label: "SRP-dependent cotranslational protein targeting to membrane, translocation"}
          - id: sec61_testis
            label: Testis-specific Sec61 complex with CG13426
            group: SEC61T-T
            complex_term: {id: GO:0005784, label: Sec61 translocon complex}
            unit_functions:
              Sec61alpha: {id: GO:0008320, label: transmembrane protein transporter activity}
  - id: sec62_sec63_complex
    label: Sec62-Sec63 complex
    role: post-translational translocation partner
    group: SEC62-63
    complex_term: {id: GO:0031207, label: Sec62/Sec63 complex}
    processes:
      - {id: GO:0031204, label: "post-translational protein targeting to membrane, translocation"}
  - id: translocon_associated_proteins
    label: Translocon-associated proteins
    role: substrate-specific translocation assistance
    description: TRAM and the delta subunit of the TRAP complex.
    group: SEC-TRAP
    complex: false