P0DOC3 · APOE_CAMDR
- ProteinApolipoprotein E
- GeneAPOE
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids317 (go to sequence)
- Protein existenceInferred from homology
- Annotation score5/5
Function
function
APOE is an apolipoprotein, a protein associating with lipid particles, that mainly functions in lipoprotein-mediated lipid transport between organs via the plasma and interstitial fluids. APOE is a core component of plasma lipoproteins and is involved in their production, conversion and clearance. Apolipoproteins are amphipathic molecules that interact both with lipids of the lipoprotein particle core and the aqueous environment of the plasma. As such, APOE associates with chylomicrons, chylomicron remnants, very low density lipoproteins (VLDL) and intermediate density lipoproteins (IDL) but shows a preferential binding to high-density lipoproteins (HDL). It also binds a wide range of cellular receptors including the LDL receptor/LDLR and the very low-density lipoprotein receptor/VLDLR that mediate the cellular uptake of the APOE-containing lipoprotein particles. Finally, APOE has also a heparin-binding activity and binds heparan-sulfate proteoglycans on the surface of cells, a property that supports the capture and the receptor-mediated uptake of APOE-containing lipoproteins by cells.
Features
Showing features for binding site.
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Keywords
- Molecular function
- Biological process
- Ligand
Names & Taxonomy
Protein names
- Recommended nameApolipoprotein E
- Short namesApo-E
Gene names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Artiodactyla > Tylopoda > Camelidae > Camelus
Accessions
- Primary accessionP0DOC3
Subcellular Location
UniProt Annotation
GO Annotation
Note: In the plasma, APOE is associated with chylomicrons, chylomicrons remnants, VLDL, LDL and HDL lipoproteins. Lipid poor oligomeric APOE is associated with the extracellular matrix in a calcium- and heparan-sulfate proteoglycans-dependent manner. Lipidation induces the release from the extracellular matrix. Colocalizes with CD63 and PMEL at exosomes and in intraluminal vesicles within multivesicular endosomes.
Keywords
- Cellular component
PTM/Processing
Features
Showing features for signal, chain, modified residue, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-18 | |||||
Sequence: MKALWVALVVTLLAGCRA | ||||||
Chain | PRO_0000437471 | 19-317 | Apolipoprotein E | |||
Sequence: EVEPEPEPEVQLGQEQPEWQGSQPWELALGRLWDYLRWVQTLSDQVQEELLSTQVTQELTALMEETMKEVKAYKAELEEQLSPVAQETRARLSKELQAAQARLGTDMEDLRSRLAHYRNEVQAMLGQTTDELRNRLASHLRKLRKRLLRDAEDLQKRLAVYRAGAVEGAERSVSALRERLGPLVEQGRLGTATTSTLGSQPLRERAEAWGQKLRGRLEAVGARAQDRLDKMREQLEEVRAKVEEQASQMRLQAETFQARLKGWFQPLVEDLQRQWAGLVEKVQQLAVGTTPTPAASKNQ | ||||||
Modified residue | 142 | Methionine sulfoxide | ||||
Sequence: M | ||||||
Glycosylation | 211 | O-linked (GalNAc...) threonine | ||||
Sequence: T | ||||||
Glycosylation | 310 | O-linked (GalNAc...) threonine | ||||
Sequence: T |
Post-translational modification
APOE exists as multiple glycosylated and sialylated glycoforms within cells and in plasma. The extent of glycosylation and sialylation are tissue and context specific.
Glycated in plasma VLDL.
Phosphorylated by FAM20C in the extracellular medium.
Keywords
- PTM
PTM databases
Interaction
Subunit
Homotetramer. May interact with ABCA1; functionally associated with ABCA1 in the biogenesis of HDLs. May interact with APP/A4 amyloid-beta peptide; the interaction is extremely stable in vitro but its physiological significance is unclear. May interact with MAPT. May interact with MAP2. In the cerebrospinal fluid, interacts with secreted SORL1. Interacts with PMEL; this allows the loading of PMEL luminal fragment on ILVs to induce fibril nucleation.
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for repeat, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Repeat | 79-100 | 1 | ||||
Sequence: ALMEETMKEVKAYKAELEEQLS | ||||||
Region | 79-254 | 8 X 22 AA approximate tandem repeats | ||||
Sequence: ALMEETMKEVKAYKAELEEQLSPVAQETRARLSKELQAAQARLGTDMEDLRSRLAHYRNEVQAMLGQTTDELRNRLASHLRKLRKRLLRDAEDLQKRLAVYRAGAVEGAERSVSALRERLGPLVEQGRLGTATTSTLGSQPLRERAEAWGQKLRGRLEAVGARAQDRLDKMREQLE | ||||||
Repeat | 101-122 | 2 | ||||
Sequence: PVAQETRARLSKELQAAQARLG | ||||||
Repeat | 123-144 | 3 | ||||
Sequence: TDMEDLRSRLAHYRNEVQAMLG | ||||||
Repeat | 145-166 | 4 | ||||
Sequence: QTTDELRNRLASHLRKLRKRLL | ||||||
Region | 157-167 | LDL and other lipoprotein receptors binding | ||||
Sequence: HLRKLRKRLLR | ||||||
Repeat | 167-188 | 5 | ||||
Sequence: RDAEDLQKRLAVYRAGAVEGAE | ||||||
Repeat | 189-210 | 6 | ||||
Sequence: RSVSALRERLGPLVEQGRLGTA | ||||||
Region | 209-289 | Lipid-binding and lipoprotein association | ||||
Sequence: TATTSTLGSQPLRERAEAWGQKLRGRLEAVGARAQDRLDKMREQLEEVRAKVEEQASQMRLQAETFQARLKGWFQPLVEDL | ||||||
Repeat | 211-232 | 7 | ||||
Sequence: TTSTLGSQPLRERAEAWGQKLR | ||||||
Repeat | 233-254 | 8 | ||||
Sequence: GRLEAVGARAQDRLDKMREQLE | ||||||
Region | 265-317 | Homooligomerization | ||||
Sequence: SQMRLQAETFQARLKGWFQPLVEDLQRQWAGLVEKVQQLAVGTTPTPAASKNQ | ||||||
Region | 277-289 | Specificity for association with VLDL | ||||
Sequence: RLKGWFQPLVEDL |
Sequence similarities
Belongs to the apolipoprotein A1/A4/E family.
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length317
- Mass (Da)36,035
- Last updated2016-10-05 v1
- Checksum23EF479EC32DFD3E