APOC2

Protein identityUniProt · HPA

UniProt accession

P02655

Gene

APOC2

Ensembl

ENSG00000234906

Chromosome

19

Canonical length

101 aa

Protein class

Candidate cardiovascular disease genes, Disease related genes, Human disease related genes, Metabolic proteins, Plasma proteins, Predicted secreted proteins

Secretome location

Secreted to blood

OverviewNCBI Gene

This gene encodes a lipid-binding protein belonging to the apolipoprotein gene family. The protein is secreted in plasma where it is a component of very low density lipoprotein. This protein activates the enzyme lipoprotein lipase, which hydrolyzes triglycerides and thus provides free fatty acids for cells. Mutations in this gene cause hyperlipoproteinemia type IB, characterized by hypertriglyceridemia, xanthomas, and increased risk of pancreatitis and early atherosclerosis. This gene is present in a cluster with other related apolipoprotein genes on chromosome 19. Naturally occurring read-through transcription exists between this gene and the neighboring upstream apolipoprotein C-IV (APOC4) gene. [provided by RefSeq, Mar 2011]

Canonical amino-acid sequenceUniProt

101 residues, UniProt reviewed canonical sequence.

>P02655|APOC2
     1  MGTRLLPALF LVLLVLGFEV QGTQQPQQDE MPSPTFLTQV KESLSSYWES AKTAAQNLYE
    61  KTYLPAVDEK LRDLYSKSTA AMSTYTGIFT DQVLSVLKGE E

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against APOC2 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)

0.54

Highest tissue expression

8,988 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about APOC2.

Disease | AllUniProt

Conditions APOC2 is implicated in, by any mechanism.

• Hyperlipoproteinemia 1B (HLPP1B) MIM:207750

Disease | GeneticClinVar

18 pathogenic / likely-pathogenic of 132 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• Familial apolipoprotein C-II deficiency
• Cardiovascular phenotype
• APOLIPOPROTEIN C-II (PADOVA)
• APOLIPOPROTEIN C-II (ST. MICHAEL)
• APOLIPOPROTEIN C-II (HAMBURG)

ReferencesPubMed · IEDB

Publications for APOC2 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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)

0.94

gnomAD pLI

0.4

gnomAD missense Z

0.33

DepMap mean gene effect

-0.01

DepMap dependency class

selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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
• chylomicron remodeling
• high-density lipoprotein particle clearance
• lipid catabolic process
• lipoprotein catabolic process
• negative regulation of cholesterol transport
• negative regulation of lipid metabolic process
• negative regulation of receptor-mediated endocytosis
• negative regulation of very-low-density lipoprotein particle clearance
• phospholipid efflux
• positive regulation of fatty acid biosynthetic process
• positive regulation of triglyceride catabolic process
• positive regulation of very-low-density lipoprotein particle remodeling
• reverse cholesterol transport
• triglyceride homeostasis
• triglyceride-rich lipoprotein particle remodeling
• very-low-density lipoprotein particle remodeling
• positive regulation of phospholipid catabolic process

Molecular functions

• lipase inhibitor activity
• lipid binding
• lipoprotein lipase activator activity
• molecular function activator activity
• phospholipase activator activity
• phospholipase binding

Cellular components

• chylomicron
• early endosome
• extracellular region
• extracellular space
• intermediate-density lipoprotein particle
• low-density lipoprotein particle
• spherical high-density lipoprotein particle
• very-low-density lipoprotein particle

Protein domainsUniProt · Pfam · InterPro

• Apolipoprotein C-II
• ApoC-II domain superfamily
• Apolipoprotein C-II

KeywordsUniProt

• Chylomicron
• Glycoprotein
• HDL
• Hyperlipidemia
• LDL
• Lipid degradation
• Lipid metabolism
• Lipid transport
• Secreted
• Sialic acid
• Signal
• Transport
• VLDL

InteractionsUniProt · HPA

Protein binding partners of APOC2 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• LPL
• CLU