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APOB apolipoprotein B [ Homo sapiens (human) ]

Gene ID: 338, updated on 23-Oct-2014
Official Symbol
APOBprovided by HGNC
Official Full Name
apolipoprotein Bprovided by HGNC
Primary source
HGNC:HGNC:603
See related
Ensembl:ENSG00000084674; HPRD:00133; MIM:107730; Vega:OTTHUMG00000090785
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Homo sapiens
Lineage
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as
FLDB; LDLCQ4
Summary
This gene product is the main apolipoprotein of chylomicrons and low density lipoproteins. It occurs in plasma as two main isoforms, apoB-48 and apoB-100: the former is synthesized exclusively in the gut and the latter in the liver. The intestinal and the hepatic forms of apoB are encoded by a single gene from a single, very long mRNA. The two isoforms share a common N-terminal sequence. The shorter apoB-48 protein is produced after RNA editing of the apoB-100 transcript at residue 2180 (CAA->UAA), resulting in the creation of a stop codon, and early translation termination. Mutations in this gene or its regulatory region cause hypobetalipoproteinemia, normotriglyceridemic hypobetalipoproteinemia, and hypercholesterolemia due to ligand-defective apoB, diseases affecting plasma cholesterol and apoB levels. [provided by RefSeq, Jul 2008]
See APOB in Epigenomics, MapViewer
Location:
2p24-p23
Exon count:
29
Annotation release Status Assembly Chr Location
106 current GRCh38 (GCF_000001405.26) 2 NC_000002.12 (21001429..21044073, complement)
105 previous assembly GRCh37.p13 (GCF_000001405.25) 2 NC_000002.11 (21224301..21266945, complement)

Chromosome 2 - NC_000002.12Genomic Context describing neighboring genes Neighboring gene chromosome 2 open reading frame 43 Neighboring gene uncharacterized LOC101928271 Neighboring gene uncharacterized LOC101929195 Neighboring gene tudor domain containing 15

GeneRIFs: Gene References Into FunctionsWhat's a GeneRIF?

Professional guidelines

Description
Professional guideline
ACMG 2013

The ACMG recommends that laboratories performing clinical sequencing seek and report mutations in APOB that are pathogenic or expected to be pathogenic.

GuidelinePubMed

Associated conditions

Description Tests
Hypercholesterolemia, autosomal dominant, type B
MedGen: C1704417 OMIM: 144010 GeneReviews: Not available
Compare labs
Hypobetalipoproteinemia, familial, 1
MedGen: CN182502 OMIM: 615558 GeneReviews: Not available
Compare labs

NHGRI GWAS Catalog

Description
Biological, clinical and population relevance of 95 loci for blood lipids.
NHGRI GWA Catalog
Common variants at 30 loci contribute to polygenic dyslipidemia.
NHGRI GWA Catalog
Discovery and refinement of loci associated with lipid levels.
NHGRI GWA Catalog
Excess of rare variants in genes identified by genome-wide association study of hypertriglyceridemia.
NHGRI GWA Catalog
Familial defective apolipoprotein B-100 and increased low-density lipoprotein cholesterol and coronary artery calcification in the old order amish.
NHGRI GWA Catalog
Forty-three loci associated with plasma lipoprotein size, concentration, and cholesterol content in genome-wide analysis.
NHGRI GWA Catalog
Genetic variants in LPL, OASL and TOMM40/APOE-C1-C2-C4 genes are associated with multiple cardiovascular-related traits.
NHGRI GWA Catalog
Genetic variants influencing circulating lipid levels and risk of coronary artery disease.
NHGRI GWA Catalog
Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels.
NHGRI GWA Catalog
Genome-wide association analysis of metabolic traits in a birth cohort from a founder population.
NHGRI GWA Catalog
Genome-wide association of lipid-lowering response to statins in combined study populations.
NHGRI GWA Catalog
Genome-wide association study evaluating lipoprotein-associated phospholipase A2 mass and activity at baseline and after rosuvastatin therapy.
NHGRI GWA Catalog
Genome-wide association study pinpoints a new functional apolipoprotein B variant influencing oxidized low-density lipoprotein levels but not cardiovascular events: AtheroRemo Consortium.
NHGRI GWA Catalog
Genome-wide association study to identify single nucleotide polymorphisms (SNPs) associated with the development of erectile dysfunction in African-American men after radiotherapy for prostate cancer.
NHGRI GWA Catalog
Genome-wide characterization of shared and distinct genetic components that influence blood lipid levels in ethnically diverse human populations.
NHGRI GWA Catalog
Genome-wide screen for metabolic syndrome susceptibility Loci reveals strong lipid gene contribution but no evidence for common genetic basis for clustering of metabolic syndrome traits.
NHGRI GWA Catalog
LDL-cholesterol concentrations: a genome-wide association study.
NHGRI GWA Catalog
Loci influencing lipid levels and coronary heart disease risk in 16 European population cohorts.
NHGRI GWA Catalog
Newly identified loci that influence lipid concentrations and risk of coronary artery disease.
NHGRI GWA Catalog
Novel Loci for metabolic networks and multi-tissue expression studies reveal genes for atherosclerosis.
NHGRI GWA Catalog
Six new loci associated with blood low-density lipoprotein cholesterol, high-density lipoprotein cholesterol or triglycerides in humans.
NHGRI GWA Catalog

Replication interactions

Interaction Pubs
Knockdown of apolipoprotein B (APOB) by siRNA inhibits HIV-1 replication in HeLa P4/R5 cells PubMed

Go to the HIV-1, Human Interaction Database

  • Binding and Uptake of Ligands by Scavenger Receptors, organism-specific biosystem (from REACTOME)
    Binding and Uptake of Ligands by Scavenger Receptors, organism-specific biosystemScavenger receptors bind free extracellular ligands as the initial step in clearance of the ligands from the body (reviewed in Ascenzi et al. 2005, Areschoug and Gordon 2009, Nielsen et al. 2010). So...
  • Cell surface interactions at the vascular wall, organism-specific biosystem (from REACTOME)
    Cell surface interactions at the vascular wall, organism-specific biosystemLeukocyte extravasation is a rigorously controlled process that guides white cell movement from the vascular lumen to sites of tissue inflammation. The powerful adhesive interactions that are require...
  • Chylomicron-mediated lipid transport, organism-specific biosystem (from REACTOME)
    Chylomicron-mediated lipid transport, organism-specific biosystemChylomicrons transport triacylglycerol, phospholipid, and cholesterol derived from dietary lipid from the small intestine to other tissues of the body. Each chylomicron assembles around a single mole...
  • Disease, organism-specific biosystem (from REACTOME)
    Disease, organism-specific biosystemBiological processes are captured in Reactome by identifying the molecules (DNA, RNA, protein, small molecules) involved in them and describing the details of their interactions. From this molecular ...
  • Diseases associated with visual transduction, organism-specific biosystem (from REACTOME)
    Diseases associated with visual transduction, organism-specific biosystemThe process of vision involves two stages; the retinoid cycle which supplies and regenerates the visual chromophore required for vision and phototransduction which propagates the light signal. Defect...
  • FOXA1 transcription factor network, organism-specific biosystem (from Pathway Interaction Database)
    FOXA1 transcription factor network, organism-specific biosystem
    FOXA1 transcription factor network
  • Fat digestion and absorption, organism-specific biosystem (from KEGG)
    Fat digestion and absorption, organism-specific biosystemFat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, die...
  • Fat digestion and absorption, conserved biosystem (from KEGG)
    Fat digestion and absorption, conserved biosystemFat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, die...
  • Hemostasis, organism-specific biosystem (from REACTOME)
    Hemostasis, organism-specific biosystemHemostasis is a physiological response that culminates in the arrest of bleeding from an injured vessel. Under normal conditions the vascular endothelium supports vasodilation, inhibits platelet adhe...
  • LDL-mediated lipid transport, organism-specific biosystem (from REACTOME)
    LDL-mediated lipid transport, organism-specific biosystemLDL (low density lipoproteins) are complexes of a single molecule of apoprotein B-100 (apoB-100) non-covalently associated with triacylglycerol, free cholesterol, cholesterol esters, and phospholipid...
  • Lipid digestion, mobilization, and transport, organism-specific biosystem (from REACTOME)
    Lipid digestion, mobilization, and transport, organism-specific biosystemProcesses annotated here include the digestion of dietary lipids, sterol uptake, the formation and turnover of lipoproteins (chylomicrons, VLDL, LDL, and HDL), and the mobilization of fatty acids thr...
  • Lipoprotein metabolism, organism-specific biosystem (from REACTOME)
    Lipoprotein metabolism, organism-specific biosystemBecause of their hydrophobicity, lipids are found in the extracellular spaces of the human body primarily in the form of lipoprotein complexes. Chylomicrons form in the small intestine and transport ...
  • Metabolism, organism-specific biosystem (from REACTOME)
    Metabolism, organism-specific biosystemMetabolic processes in human cells generate energy through the oxidation of molecules consumed in the diet and mediate the synthesis of diverse essential molecules not taken in the diet as well as th...
  • Metabolism of lipids and lipoproteins, organism-specific biosystem (from REACTOME)
    Metabolism of lipids and lipoproteins, organism-specific biosystemLipids are hydrophobic but otherwise chemically diverse molecules that play a wide variety of roles in human biology. They include ketone bodies, fatty acids, triacylglycerols, phospholipids and sphi...
  • Platelet homeostasis, organism-specific biosystem (from REACTOME)
    Platelet homeostasis, organism-specific biosystemUnder normal conditions the vascular endothelium supports vasodilation, inhibits platelet adhesion and activation, suppresses coagulation, enhances fibrin cleavage and is anti-inflammatory in charact...
  • Platelet sensitization by LDL, organism-specific biosystem (from REACTOME)
    Platelet sensitization by LDL, organism-specific biosystemPhysiological concentrations (1g/L) of Low density lipoprotein (LDL) enhance platelet aggregation responses initiated by thrombin, collagen, and ADP. This enhancement involves the rapid phosphorylati...
  • Retinoid metabolism and transport, organism-specific biosystem (from REACTOME)
    Retinoid metabolism and transport, organism-specific biosystemVitamin A (all-trans-retinol) must be taken up, either as carotenes from plants, or as retinyl esters from animal food. The most prominent carotenes are alpha-carotene, lycopene, lutein, beta-cryptox...
  • Scavenging by Class A Receptors, organism-specific biosystem (from REACTOME)
    Scavenging by Class A Receptors, organism-specific biosystemClass A scavenger receptors contain an intracellular domain, a transmembrane region, a coiled-coil domain, a collagenous domain, and the SR cysteine-rich domain (reviewed in Areschoug and Gordon 2009...
  • Scavenging by Class B Receptors, organism-specific biosystem (from REACTOME)
    Scavenging by Class B Receptors, organism-specific biosystemClass B receptors have two transmembrane domains separated by an extracellular loop (reviewed in Adachi and Tsujimoto 2006, Areschoug and Gordon 2009).
  • Scavenging by Class F Receptors, organism-specific biosystem (from REACTOME)
    Scavenging by Class F Receptors, organism-specific biosystemSCARF1 (SREC-I) and SCARF2 (SREC-II) are transmembrane proteins that contain multiple extracellular EGF-like domains (Ishii et al. 2002, reviewed in Areschoug and Gordon 2009). SCARF2 may be involved...
  • Scavenging by Class H Receptors, organism-specific biosystem (from REACTOME)
    Scavenging by Class H Receptors, organism-specific biosystemSTAB1 (FEEL-1) and STAB2 (FEEL-2) are very large transmambrane proteins containing fasciclin domains, EGF-like domains, and hyaluronan-like domains (Politz et al. 2002, reviewed in Areschoug and Gord...
  • Selenium Pathway, organism-specific biosystem (from WikiPathways)
    Selenium Pathway, organism-specific biosystem
    Selenium Pathway
  • Signal Transduction, organism-specific biosystem (from REACTOME)
    Signal Transduction, organism-specific biosystemSignal transduction is a process in which extracellular signals elicit changes in cell state and activity. Transmembrane receptors sense changes in the cellular environment by binding ligands, such a...
  • Statin Pathway, organism-specific biosystem (from WikiPathways)
    Statin Pathway, organism-specific biosystemStatins inhibit endogenous cholesterol production by competitive inhibition of HMG-CoA reductase (HMGCR), the enzyme that catalyzes conversion of HMG-CoA to mevalonate, an early rate-limiting step in...
  • Visual phototransduction, organism-specific biosystem (from REACTOME)
    Visual phototransduction, organism-specific biosystemVisual phototransduction is the process by which photon absorption by visual pigment molecules in photoreceptor cells is converted to an electrical cellular response. The events in this process are p...
  • Vitamin digestion and absorption, organism-specific biosystem (from KEGG)
    Vitamin digestion and absorption, organism-specific biosystemVitamins are a diverse and chemically unrelated group of organic substances that share a common feature of being essential for normal health and well-being. They catalyze numerous biochemical reactio...
  • Vitamin digestion and absorption, conserved biosystem (from KEGG)
    Vitamin digestion and absorption, conserved biosystemVitamins are a diverse and chemically unrelated group of organic substances that share a common feature of being essential for normal health and well-being. They catalyze numerous biochemical reactio...
  • amb2 Integrin signaling, organism-specific biosystem (from Pathway Interaction Database)
    amb2 Integrin signaling, organism-specific biosystem
    amb2 Integrin signaling
Products Interactant Other Gene Complex Source Pubs Description

Markers

Homology

Gene Ontology Provided by GOA

Function Evidence Code Pubs
cholesterol transporter activity IMP
Inferred from Mutant Phenotype
more info
PubMed 
heparin binding IDA
Inferred from Direct Assay
more info
PubMed 
lipase binding IPI
Inferred from Physical Interaction
more info
PubMed 
low-density lipoprotein particle receptor binding IMP
Inferred from Mutant Phenotype
more info
PubMed 
phospholipid binding IDA
Inferred from Direct Assay
more info
PubMed 
protein binding IPI
Inferred from Physical Interaction
more info
 
Process Evidence Code Pubs
artery morphogenesis IEA
Inferred from Electronic Annotation
more info
 
blood coagulation TAS
Traceable Author Statement
more info
 
cellular response to prostaglandin stimulus IEA
Inferred from Electronic Annotation
more info
 
cellular response to tumor necrosis factor IEA
Inferred from Electronic Annotation
more info
 
cholesterol efflux IEA
Inferred from Electronic Annotation
more info
 
cholesterol homeostasis IMP
Inferred from Mutant Phenotype
more info
PubMed 
cholesterol metabolic process IMP
Inferred from Mutant Phenotype
more info
PubMed 
cholesterol transport IMP
Inferred from Mutant Phenotype
more info
PubMed 
fertilization IEA
Inferred from Electronic Annotation
more info
 
in utero embryonic development IEA
Inferred from Electronic Annotation
more info
 
leukocyte migration TAS
Traceable Author Statement
more info
 
lipoprotein biosynthetic process IEA
Inferred from Electronic Annotation
more info
 
lipoprotein catabolic process IEA
Inferred from Electronic Annotation
more info
 
lipoprotein metabolic process TAS
Traceable Author Statement
more info
 
lipoprotein transport IEA
Inferred from Electronic Annotation
more info
 
low-density lipoprotein particle clearance IMP
Inferred from Mutant Phenotype
more info
PubMed 
low-density lipoprotein particle remodeling IMP
Inferred from Mutant Phenotype
more info
PubMed 
nervous system development IEA
Inferred from Electronic Annotation
more info
 
phototransduction, visible light TAS
Traceable Author Statement
more info
 
positive regulation of cholesterol storage IDA
Inferred from Direct Assay
more info
PubMed 
positive regulation of lipid storage IDA
Inferred from Direct Assay
more info
PubMed 
positive regulation of macrophage derived foam cell differentiation IDA
Inferred from Direct Assay
more info
PubMed 
post-embryonic development IEA
Inferred from Electronic Annotation
more info
 
receptor-mediated endocytosis TAS
Traceable Author Statement
more info
 
regulation of cholesterol biosynthetic process IEA
Inferred from Electronic Annotation
more info
 
response to carbohydrate IEA
Inferred from Electronic Annotation
more info
 
response to lipopolysaccharide IEA
Inferred from Electronic Annotation
more info
 
response to selenium ion IEA
Inferred from Electronic Annotation
more info
 
response to virus IEP
Inferred from Expression Pattern
more info
PubMed 
retinoid metabolic process TAS
Traceable Author Statement
more info
 
small molecule metabolic process TAS
Traceable Author Statement
more info
 
sperm motility IEA
Inferred from Electronic Annotation
more info
 
spermatogenesis IEA
Inferred from Electronic Annotation
more info
 
triglyceride catabolic process IEA
Inferred from Electronic Annotation
more info
 
triglyceride mobilization IEA
Inferred from Electronic Annotation
more info
 
very-low-density lipoprotein particle assembly IC
Inferred by Curator
more info
PubMed 
Component Evidence Code Pubs
Golgi apparatus IDA
Inferred from Direct Assay
more info
 
actin cytoskeleton IDA
Inferred from Direct Assay
more info
 
chylomicron IDA
Inferred from Direct Assay
more info
PubMed 
chylomicron remnant TAS
Traceable Author Statement
more info
PubMed 
clathrin-coated endocytic vesicle membrane TAS
Traceable Author Statement
more info
 
cytoplasm IDA
Inferred from Direct Assay
more info
 
cytosol TAS
Traceable Author Statement
more info
 
early endosome TAS
Traceable Author Statement
more info
 
endocytic vesicle lumen TAS
Traceable Author Statement
more info
 
endoplasmic reticulum lumen TAS
Traceable Author Statement
more info
 
endoplasmic reticulum membrane TAS
Traceable Author Statement
more info
 
endosome lumen TAS
Traceable Author Statement
more info
 
endosome membrane TAS
Traceable Author Statement
more info
 
extracellular region TAS
Traceable Author Statement
more info
 
extracellular space ISS
Inferred from Sequence or Structural Similarity
more info
 
extracellular vesicular exosome IDA
Inferred from Direct Assay
more info
 
intermediate-density lipoprotein particle IDA
Inferred from Direct Assay
more info
PubMed 
intracellular membrane-bounded organelle TAS
Traceable Author Statement
more info
PubMed 
low-density lipoprotein particle IDA
Inferred from Direct Assay
more info
PubMed 
mature chylomicron IDA
Inferred from Direct Assay
more info
PubMed 
plasma membrane IDA
Inferred from Direct Assay
more info
 
plasma membrane TAS
Traceable Author Statement
more info
 
very-low-density lipoprotein particle IDA
Inferred from Direct Assay
more info
PubMed 
Preferred Names
apolipoprotein B-100
Names
apolipoprotein B-100
apoB-48
apoB-100
apo B-100
mutant Apo B 100
apolipoprotein B48
apolipoprotein B (including Ag(x) antigen)
NP_000375.2

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

Genomic

  1. NG_011793.1 

    Range
    5001..47645
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. NM_000384.2NP_000375.2  apolipoprotein B-100 precursor

    See proteins identical to NP_000375.2

    Status: REVIEWED

    Source sequence(s)
    AB208846, BC051278, J02610, X04506, X04714
    Consensus CDS
    CCDS1703.1
    UniProtKB/Swiss-Prot
    P04114
    UniProtKB/TrEMBL
    Q59HB3
    UniProtKB/TrEMBL
    Q7Z7Q0
    Related
    ENSP00000233242, OTTHUMP00000115994, ENST00000233242, OTTHUMT00000207571
    Conserved Domains (6) summary
    pfam12491
    Location:44944551
    ApoB100_C; Apolipoprotein B100 C terminal
    COG1340
    Location:42584523
    COG1340; Uncharacterized archaeal coiled-coil protein [Function unknown]
    pfam01347
    Location:46597
    Vitellogenin_N; Lipoprotein amino terminal region
    pfam06448
    Location:9581072
    DUF1081; Domain of Unknown Function (DUF1081)
    pfam09172
    Location:632945
    DUF1943; Domain of unknown function (DUF1943)
    cl17244
    Location:14481865
    OM_channels; Porin superfamily. These outer membrane channels share a beta-barrel structure that differ in strand and shear number. Classical (gram-negative ) porins are non-specific channels for small hydrophillic molecules and form 16 beta-stranded barrels (16,20) ...

RefSeqs of Annotated Genomes: Homo sapiens Annotation Release 106

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCh38 Primary Assembly

Genomic

  1. NC_000002.12 

    Range
    21001429..21044073
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

Alternate HuRef

Genomic

  1. AC_000134.1 

    Range
    20956976..20999627
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

Alternate CHM1_1.1

Genomic

  1. NC_018913.2 

    Range
    21153564..21196210
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)