APOB Gene Description:
The APOB gene provides instructions for making two versions of the apolipoprotein B protein, a short version called apolipoprotein B-48 and a longer version known as apolipoprotein B-100. Both of these proteins are components of lipoproteins, which are particles that carry fats and fat-like substances (such as cholesterol) in the blood.
Apolipoprotein B-48 is produced in the intestine, where it is a building block of a type of lipoprotein called a chylomicron. As food is digested after a meal, chylomicrons are formed to carry fat and cholesterol from the intestine into the bloodstream. Chylomicrons are also necessary for the absorption of certain fat-soluble vitamins such as vitamin E and vitamin A.
Apolipoprotein B-100, which is produced in the liver, is a component of several other types of lipoproteins. Specifically, this protein is a building block of very low-density lipoproteins (VLDLs), intermediate-density lipoproteins (IDLs), and low-density lipoproteins (LDLs). These related molecules all transport fats and cholesterol in the bloodstream.
LDLs are the primary carriers of cholesterol in the blood. Apolipoprotein B-100 allows LDLs to attach to specific receptors on the surface of cells, particularly in the liver. Once attached, the receptors transport LDLs into the cell, where they are broken down to release cholesterol. The cholesterol is then used by the cell, stored, or removed from the body.
Genetic Lifehacks articles that include APOB variants (SNPs):