trans-Golgi network

GO:0005802 · Membrane organelle · Membrane bounded organelle · Proposed

The network of interconnected tubular and cisternal structures located within the Golgi apparatus on the side distal to the endoplasmic reticulum, from which secretory vesicles emerge. The trans-Golgi network is important in the later stages of protein secretion where it is thought to play a key role in the sorting and targeting of secreted proteins to the correct destination. [GO:0005802]

Synonyms: TGN; trans Golgi network

Part of: Golgi apparatus (GO:0005794)

Has part: trans-Golgi network membrane (GO:0032588)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
trans-Golgi network lipid bilayer	Lipid	part of	Reviewed label only (reviewed name; no accession asserted)			ESSENTIAL	Lipid-bilayer constituent of the trans-Golgi network membrane. `GO:0032588` GO:0032588 defines the trans-Golgi network membrane as the lipid bilayer around compartments that make up the trans-Golgi network.

Taxonomic distribution

NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Holthuis et al. characterized Tlg1p and Tlg2p as Saccharomyces syntaxins in the TGN/endosomal system. [DOI:10.1093/emboj/17.1.113]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model in which Ent3p and Ent5p adaptor functions in protein trafficking between the trans-Golgi network and endosomes were dissected. [DOI:10.1091/MBC.E06-11-1000]

Functions

trans-Golgi network/endosome protein sorting — The yeast trans-Golgi network sorts cargo between late Golgi and endosomal compartments on routes toward the vacuole.
- GO:0005802 GO:0005802 defines the trans-Golgi network as the late-Golgi sorting and targeting compartment for secreted proteins.
- DOI:10.1091/MBC.E06-11-1000 Copic et al. 2007 studied cargo-specific protein trafficking between the trans-Golgi network and endosomes in Saccharomyces cerevisiae.

Mechanism graphs

Yeast trans-Golgi network exchanges cargo with endosomes (FUNCTION)

In Saccharomyces cerevisiae, the trans-Golgi network/endosomal system supports cargo transport between late Golgi and endosomal compartments.

Subject	Predicate	Object	Evidence
trans-Golgi network membrane	bounds	trans-Golgi network	`GO:0032588` GO:0032588 defines the membrane surrounding trans-Golgi network compartments.
trans-Golgi network	is part of	Golgi apparatus	`GO:0005802` GO:0005802 defines the trans-Golgi network as a distal Golgi sorting compartment. `GO:0098791` GO:0098791 defines a Golgi apparatus subcompartment as a membrane-bounded compartment that is part of the Golgi apparatus.
trans-Golgi network	supports	TGN/endosomal protein sorting	`DOI:10.1093/emboj/17.1.113` Holthuis et al. 1998 characterized the yeast TGN/endosomal system through the syntaxins Tlg1p and Tlg2p. `DOI:10.1091/MBC.E06-11-1000` Copic et al. 2007 studied Ent3p/Ent5p roles in trafficking proteins between the yeast TGN and endosomes.
TGN/endosomal protein sorting	connects	endosome	`DOI:10.1091/MBC.E06-11-1000` Copic et al. 2007 framed Ent3p/Ent5p-dependent cargo sorting as protein trafficking between the trans-Golgi network and endosomes in yeast.

Discussions

CURATION_TODO (OPEN): Resolve an exact source-neutral grounding for the lipid constituent of the trans-Golgi network membrane. The record is exactly grounded to GO:0005802 and GO:0032588 identifies the surrounding trans-Golgi network membrane, but the membrane lipid-bilayer constituent is intentionally left as reviewed-label-only until an exact source-neutral lipid or membrane-constituent CURIE is curated.
INTERPRETATION (RESOLVED): Keep Tlg SNAREs and Ent adaptor proteins out of the trans-Golgi network structural-component list until exact source-neutral families are curated and a constituent-versus-trafficking-machinery boundary is reviewed. Holthuis et al. 1998 and Copic et al. 2007 support TGN/endosomal traffic through Tlg1p, Tlg2p, Ent3p and Ent5p, but this initial whole-compartment record does not treat those trafficking factors as lipid-bilayer constituents of the TGN itself.

Evidence

GO:0005802 Gene Ontology cellular-component term for trans-Golgi network.
GO:0098791 Gene Ontology cellular-component parent term for Golgi apparatus subcompartment.
GO:0005794 Gene Ontology cellular-component term for Golgi apparatus.
GO:0032588 Gene Ontology cellular-component term for trans-Golgi network membrane.
GO:0005768 Gene Ontology cellular-component term for endosome.
DOI:10.1093/emboj/17.1.113 Holthuis et al. 1998, 'Two syntaxin homologues in the TGN/endosomal system of yeast', EMBO Journal.
DOI:10.1091/MBC.E06-11-1000 Copic et al. 2007, 'Ent3p and Ent5p exhibit cargo-specific functions in trafficking proteins between the trans-Golgi network and the endosomes in yeast', Molecular Biology of the Cell.

Curation history

2026-09-14T04:10:40Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-14T04:11:42Z codex · EXPANDED_RECORD — Added Golgi-subcompartment parentage, Golgi-apparatus parthood, the trans-Golgi network membrane as a part, a reviewed-label-only lipid bilayer component, Saccharomyces scope, TGN/endosomal protein-sorting function, GO/DOI evidence, a nonmechanistic TGN-endosome graph, and lipid-grounding plus trafficking-factor boundary discussions.
2026-09-14T04:25:51Z codex · FIX_DISCUSSION_ANCHOR — Retargeted the TGN trafficking-factor boundary discussion from a bare components section anchor to the yeast_tgn_endosomal_traffic graph anchor required by corpus integrity checks.
2026-09-14T04:32:56Z codex · ADDRESS_REVIEW — Addressed #878 by narrowing the Saccharomyces taxonomic-scope and canonical-example notes so each stays within the single Holthuis or Copic reference attached to the row.

Source: data/structures/membrane_organelle/trans_golgi_network.yaml