lipid droplet

GO:0005811 · Inclusion · Inclusion body · Proposed

An intracellular non-membrane-bounded organelle comprising a matrix of coalesced lipids surrounded by a phospholipid monolayer. May include associated proteins. [GO:0005811]

Synonyms: adiposome; lipid body; lipid particle

Has part: monolayer-surrounded lipid storage body outer lipid monolayer (GO:0034430)

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
triglyceride	Small molecule	part of	`CHEBI:17855`			CONDITIONAL	Neutral storage-lipid class that accumulates in the hydrophobic droplet core. `PMID:29397034` Graef 2018 reviews budding-yeast lipid droplets as organelles dynamically storing neutral triacylglycerols and steryl esters. `DOI:10.1016/j.bbalip.2011.07.015` Grillitsch et al. 2011 analyzed the Saccharomyces cerevisiae lipid-droplet lipidome and proteome.
sterol ester	Small molecule	part of	`CHEBI:35915`			CONDITIONAL	Neutral storage-lipid class that accumulates with triglycerides in the hydrophobic droplet core. `PMID:29397034` Graef 2018 reviews steryl esters together with triacylglycerols as the main stored neutral lipids of budding-yeast lipid droplets. `DOI:10.1016/j.bbalip.2011.07.015` Grillitsch et al. 2011 measured steryl-esters and triacylglycerols in Saccharomyces cerevisiae lipid particles/droplets.

Taxonomic distribution

NCBITaxon:4751 Fungi — VARIABLE: Lipid droplets are characterized in budding yeast and in the filamentous fungus Aspergillus oryzae, but this first record does not assert ubiquity across all fungi. [DOI:10.1111/mmi.15170]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding yeast species used to define lipid-droplet neutral-lipid storage and lipidome/proteome composition. [DOI:10.1016/j.bbalip.2011.07.015]

Functions

neutral lipid storage — Lipid droplets sequester hydrophobic triglycerides and sterol esters as neutral-lipid reserves that can be mobilized by lipases and hydrolases.
- DOI:10.1007/s00018-015-1903-5 Wang 2015 reviews lipid-droplet biogenesis, growth, inheritance, degradation and lipolytic mobilization in budding yeast.
- PMID:29397034 Graef 2018 reviews budding-yeast lipid droplets as dedicated stores of triacylglycerols and steryl esters.

Mechanism graphs

Neutral lipids coalesce inside a monolayer droplet (ASSEMBLY)

Triglycerides and sterol esters form the hydrophobic core of a lipid droplet, which is surrounded by a phospholipid monolayer and stores neutral lipids for later mobilization.

Subject	Predicate	Object	Evidence
triglyceride	forms core of	lipid droplet	`PMID:29397034` Graef 2018 reviews triacylglycerols as a major neutral-lipid class dynamically stored in budding-yeast lipid droplets.
sterol ester	forms core of	lipid droplet	`PMID:29397034` Graef 2018 reviews steryl esters as a major neutral-lipid class dynamically stored in budding-yeast lipid droplets.
monolayer-surrounded lipid storage body outer lipid monolayer	surrounds	lipid droplet	`GO:0005811` The GO lipid droplet definition describes a coalesced-lipid matrix surrounded by a phospholipid monolayer.
lipid droplet	stores	stored neutral lipids	`DOI:10.1007/s00018-015-1903-5` Wang 2015 reviews storage and mobilization of neutral lipids in budding-yeast lipid droplets.

Evidence

GO:0005811 Gene Ontology cellular-component term for lipid droplet.
DOI:10.1007/s00018-015-1903-5 Wang 2015, Lipid droplet dynamics in budding yeast, Cellular and Molecular Life Sciences.
PMID:29397034 Graef 2018, Lipid droplet-mediated lipid and protein homeostasis in budding yeast, FEBS Letters.
DOI:10.1016/j.bbalip.2011.07.015 Grillitsch et al. 2011, Lipid particles/droplets of the yeast Saccharomyces cerevisiae revisited: lipidome meets proteome, Biochimica et Biophysica Acta.
DOI:10.1111/mmi.15170 Al Mamun, Reza, and Islam 2023, Identification of novel proteins regulating lipid droplet biogenesis in filamentous fungi, Molecular Microbiology.

Curation history

2026-09-10T10:20:26Z claude · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-10T10:22:09Z claude · EXPANDED_RECORD — Added GO exact synonyms and monolayer parthood, ChEBI-grounded triglyceride and sterol-ester core components, fungal taxonomic scope, a Saccharomyces cerevisiae S288C canonical example, neutral-lipid storage function, record-level evidence and a nonmechanistic neutral-lipid storage graph.
2026-09-10T10:31:24Z claude · ADDRESS_REVIEW — Resolved #346 by correcting the Al Mamun lipid-droplet citation year and title; resolved #347 by changing the budding-yeast canonical example from strain-specific Saccharomyces cerevisiae S288C to species-level Saccharomyces cerevisiae.

Source: data/structures/inclusion/lipid_droplet.yaml