Apolipoprotein B

Function

Apolipoprotein B is a major protein constituent of chylomicrons (apo B-48), LDL (apo B-100) and VLDL (apo B-100). Apo B-100 functions as a recognition signal for the cellular binding and internalization of LDL particles by the apoB/E receptor.

Involvement in disease

Hypobetalipoproteinemia, familial, 1

FHBL1

A disorder of lipid metabolism characterized by less than 5th percentile age- and sex-specific levels of low density lipoproteins, and dietary fat malabsorption. Clinical presentation may vary from no symptoms to severe gastrointestinal and neurological dysfunction similar to abetalipoproteinemia.

None

The disease is caused by variants affecting the gene represented in this entry. Most cases of FHBL1 result from nonsense mutations in the APOB gene that lead to a premature stop codon, which generate prematurely truncated apo B protein products (PubMed:21981844).

Hypercholesterolemia, familial, 2

FHCL2

A form of hypercholesterolemia, a disorder of lipoprotein metabolism characterized by elevated serum low-density lipoprotein (LDL) cholesterol levels, which result in excess deposition of cholesterol in tissues and leads to xanthelasma, xanthomas, accelerated atherosclerosis and increased risk of premature coronary heart disease. FHCL2 inheritance is autosomal dominant.

None

The disease is caused by variants affecting the gene represented in this entry.

Defects in APOB associated with defects in other genes (polygenic) can contribute to hypocholesterolemia.

Post-translational modifications

Palmitoylated; structural requirement for proper assembly of the hydrophobic core of the lipoprotein particle.

Cellular localization

• Cytoplasm
• Secreted
• Lipid droplet

Alternative names

• Apolipoprotein B-100
• Apo B-100
• APOB

Database links

• entrezGene:338
• omim:107730
• swissprot:P04114

Target type

Proteins

Molecular weight

515605Da