APOC3
Apolipoprotein C-III
Also known as: Apo-C3, Apo-CIII, ApoC-3, ApoC-III, APOC3_HUMAN, APOCIII
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P02656
- Gene
- APOC3
- Ensembl
- ENSG00000110245
- Chromosome
- 11
- Canonical length
- 99 aa
- Protein class
- Cancer-related genes, Candidate cardiovascular disease genes, Disease related genes, FDA approved drug targets, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted secreted proteins
- Subcellular location
- Nucleoplasm,Nucleoli,Cell Junctions
- Secretome location
- Secreted to blood
OverviewNCBI Gene
This gene encodes a protein component of triglyceride (TG)-rich lipoproteins (TRLs) including very low density lipoproteins (VLDL), high density lipoproteins (HDL) and chylomicrons. The encoded protein plays a role in role in the metabolism of these TRLs through multiple modes. This protein has been shown to promote the secretion of VLDL1, inhibit lipoprotein lipase enzyme activity, and delay catabolism of TRL remnants. Mutations in this gene are associated with low plasma triglyceride levels and reduced risk of ischemic cardiovascular disease, and hyperalphalipoproteinemia, which is characterized by elevated levels of high density lipoprotein (HDL) and HDL cholesterol in human patients. This gene and other related genes comprise an apolipoprotein gene cluster on chromosome 11. [provided by RefSeq, Sep 2017]
Canonical amino-acid sequenceUniProt
99 residues, UniProt reviewed canonical sequence.
>P02656|APOC3
1 MQPRVLLVVA LLALLASARA SEAEDASLLS FMQGYMKHAT KTAKDALSSV QESQVAQQAR
61 GWVTDGFSSL KDYWSTVKDK FSEFWDLDPE VRPTSAVAALocalizationUniProt · AlphaFold · HPA
Whether an antibody against APOC3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.
- Antibody reachability
- Secreted
- Secreted
- Yes
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.55
- Highest tissue expression
- 28,691 nTPM
Expression across tissuesHPA
Tissue
- liver: 28,691 nTPM
- small intestine: 1,137 nTPM
- duodenum: 853 nTPM
- kidney: 17 nTPM
- spleen: 7 nTPM
- colon: 6.2 nTPM
Single-cell type
- hepatocytes: 97,066 nCPM
- enterocytes: 10,695 nCPM
- hepatic stellate cells: 400 nCPM
- cholangiocytes: 354 nCPM
- paneth cells: 344 nCPM
- kupffer cells: 210 nCPM
Immune cell
- basophil: 0 nTPM
- classical monocyte: 0 nTPM
- eosinophil: 0 nTPM
- gdT-cell: 0 nTPM
- intermediate monocyte: 0 nTPM
- MAIT T-cell: 0 nTPM
Brain region
- cerebral cortex: 0.3 nTPM
- white matter: 0.2 nTPM
- amygdala: 0.1 nTPM
- basal ganglia: 0.1 nTPM
- cerebellum: 0.1 nTPM
- hippocampal formation: 0.1 nTPM
DiseaseUniProt · ClinVar · IEDB · PubMed
Four sources answering four different questions about APOC3.
Disease | AllUniProt
Conditions APOC3 is implicated in, by any mechanism.
- Hyperalphalipoproteinemia 2 (HALP2) MIM:614028
Disease | GeneticClinVar
2 pathogenic / likely-pathogenic of 84 ClinVar records.
Conditions with pathogenic or likely-pathogenic variants.
- Apolipoprotein C-III, nonglycosylated
- Apolipoprotein c-III deficiency
Disease | ImmuneIEDB
Conditions an epitope on APOC3 was assayed in.
- rheumatoid arthritis B cell
Genetic constraint and essentialitygnomAD · DepMap
Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.
- gnomAD LOEUF (loss-of-function intolerance)
- 1.76
- gnomAD pLI
- 0.01
- gnomAD missense Z
- -0.06
- DepMap mean gene effect
- 0.03
- DepMap dependency class
- none
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Biological processes
- cholesterol efflux
- cholesterol homeostasis
- chylomicron remnant clearance
- G protein-coupled receptor signaling pathway
- high-density lipoprotein particle remodeling
- lipoprotein metabolic process
- negative regulation of cholesterol import
- negative regulation of fatty acid biosynthetic process
- negative regulation of lipid catabolic process
- negative regulation of lipid metabolic process
- negative regulation of low-density lipoprotein particle clearance
- negative regulation of receptor-mediated endocytosis
- negative regulation of triglyceride catabolic process
- negative regulation of very-low-density lipoprotein particle clearance
- negative regulation of very-low-density lipoprotein particle remodeling
- phospholipid efflux
- regulation of Cdc42 protein signal transduction
- reverse cholesterol transport
- triglyceride catabolic process
- triglyceride homeostasis
- triglyceride metabolic process
- very-low-density lipoprotein particle assembly
- negative regulation of high-density lipoprotein particle clearance
Molecular functions
- cholesterol binding
- high-density lipoprotein particle receptor binding
- lipase inhibitor activity
- phospholipid binding
Cellular components
Protein domainsUniProt · Pfam · InterPro
- Apolipoprotein CIII
- Apolipoprotein CIII superfamily
- Apolipoprotein CIII (Apo-CIII)
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads APOC3 as an antibody target. Whether an autoantibody or antibody against APOC3 could matter depends on whether native APOC3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
APOC3 is annotated as secreted, so native APOC3 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.
Annotation status
The present source text does not explicitly label APOC3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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