Sterolin

• OMIM: 605459
• UniProt: Q9H222

• OMIM: 605460
• UniProt: Q9H221

Sterolin ( ABCG5/G8-Effluxpumpe ), the membrane protein which excess cholesterol and phytosterols pumped out of liver cells in a mammal, according to which these substances flow into the gall bladder. A lesser extent is found in the membrane of Sterolin enterocytes of the intestine. The power for the pumping action is provided by ATP. It is therefore in Sterolin a membrane-bound ATPase, or more precisely to an ABC transporter.

Sterolin is a heterodimer of the two half- transporters ABCG5 and ABCG8. Mutations in each of the two genes may affect the operation of Sterolin and lead to the ( rare hereditary ) sitosterolaemia. Other mutations increase the pump activity and lead to increased risk of developing gallstones ( GBD4 ).

The transport equation for ABC transporters ( efflux ):

In a study of Chileans a variant of ABCG5 was associated with hypercholesterolemia. Using a variant of ABCG8 was found in a Taiwanese study, a similar relationship.