lipophagy

traitmech:000644 · CLASS · PROPOSED

An autophagy phenotype in which a microbial cell degrades its lipid droplets by delivering them to lysosomal or vacuolar compartments.

Trait evidence (3)

DOI:10.1091/mbc.e13-08-0448
LDs can also be turned over in vacuoles/lysosomes by a process that morphologically resembles microautophagy.

PMID:24258026, PMC3890349. Scientific abstract directly read in DOI-matched Europe PMC metadata and XML abstract2, not the precis. Results sec9 and Methods sec12-sec15 were read. Purified, trypsin-treated vacuoles, lipid analysis and TAG-lipase assays separate uptake from breakdown in Saccharomyces cerevisiae. The atg1/atg15 comparisons distinguish delivery, vacuolar catabolism and compensating cytosolic lipolysis. BY4742-derived reporter/mutant hosts are not verified natural exemplars. Actual figures and supplements were not inspected.
DOI:10.1016/j.devcel.2024.01.014
Upon nutrient exhaustion, cells consume LDs via gradual lipolysis or via lipophagy, the en bloc uptake of LDs into the vacuole.

PMID:38354739. Scientific abstract directly read in Europe PMC with matching DOI. The LDO/Vac8 vCLIP contact site supports starvation-induced yeast uptake. This source operationally calls en bloc uptake lipophagy; docking or uptake alone is not direct proof of completed lipid degradation. Shared Vac8 use links this route to nuclear microautophagy without equating the cargo phenotypes. Full text, Methods, actual figures and strain provenance were not inspected.
DOI:10.1080/15548627.2024.2325297
We find that the degradation of LD surface proteins relies on autophagy and can occur independently of lipophagy.

PMID:38425021, PMC11210923. Scientific ABSTRACT paragraph directly read and exact-matched in DOI-matched NCBI PMC XML at https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pmc&id=11210923&retmode=xml. Europe PMC and PubMed abstract fields return only abbreviations; they do not verify this quote. The retrieved XML has no body. The yeast study separates engulfment from surface-protein processing and reports glucose-concentration-dependent, ATG1-independent uptake. This does not establish lipid catabolism from a protein marker alone. Full Methods, figures and supplements were not inspected.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.1091/mbc.e13-08-0448

Parent traits (1)

autophagy traitmech:000638

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Review cargo-defined scope against source and GO conventions.

CURATION TODO OPEN lipophagy-scope-and-go-alignment · raised by codex · 2026-10-06

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

The 2014 study supports vacuolar lipid-droplet catabolism via a microautophagy-like route. The two 2024 abstracts also use lipophagy operationally for uptake; the present phenotype retains the autophagy parent's degradative endpoint, not uptake alone. Current GO:0061724 (https://www.ebi.ac.uk/QuickGO/services/ontology/go/terms/GO%3A0061724) restricts lipophagy to selective macroautophagy. GO:0140504 (https://www.ebi.ac.uk/QuickGO/services/ontology/go/terms/GO%3A0140504) separately denotes microlipophagy. Both are nonobsolete biological processes, not exact organismal-phenotype xrefs. Preserve this source-attributed scope difference for human review; no universal macro/micro route, selectivity mechanism, starvation trigger or ATG inventory is asserted. Lipolysis traitmech:000190 concerns triacylglycerol hydrolysis: it can overlap lipophagy but is neither an exact synonym nor a necessary broader parent for all droplet cargo. Lipid storage, PHA granules and pigment sequestration are not equivalent degradation phenotypes. No exact synonyms or mappings are added.

Resolve route-specific flux assays and native exemplars.

KNOWLEDGE GAP OPEN lipophagy-flux-exemplars-and-mechanism · raised by codex · 2026-10-06

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

The phenotype belongs to the microbial cell performing autophagic degradation. Droplet docking, uptake, abundance changes and surface-protein processing are distinct readouts; none alone establishes completed lipid breakdown. Cytosolic lipases can also consume stored lipids. The condition-specific ATG dependence in these studies is not a universal sequence signature. Canonical examples remain unset pending independent natural-strain provenance; do not infer natural or engineered origin merely from a mutant label. Native taxon-paired protein accessions and direct functional support are needed before a causal graph is added. Shared contact machinery with nucleophagy traitmech:000643 does not make their cargo phenotypes equivalent. The third quote is directly source-matched despite the abstract API's abbreviation-only field; retain the resolver's actual inconclusive verdict rather than calling it VERIFIED.

Curation history

2026-10-06T14:27:56Z · MINTED_TRAITMECH_ID · codex
Added lipid-droplet autophagy with three DOI-backed source-matched snippets, explicit uptake/flux limits and GO-scope differences. Ignored-and-hidden novelty checks, fresh seed and pinned METPO review found no exact record. Reserved METPO:1059700 in v520 using unchanged corrected v519 parent context. Deferred unverified exemplars, mappings and protein graphs.