Fucosyltransferase 4

Fucosyltransferase 4 (also known as FUT4) is an enzyme that in humans is encoded by the FUT4 gene. This enzyme is a member of the glycosyltransferase family, specifically the fucosyltransferase subfamily. Fucosyltransferases are responsible for the biosynthesis of the polysaccharide portion of glycoconjugates.

Function

Fucosyltransferase 4 is involved in the synthesis of Lewis antigens, which are part of the ABO blood group system. These antigens are found on the surface of red blood cells and other tissues, and play a role in immune response and cell adhesion. The enzyme adds a fucose sugar to a precursor molecule, creating the Lewis antigen.

Structure

The FUT4 gene is located on the long (q) arm of chromosome 11 at position 21. The gene spans approximately 8.5 kilobases and contains six exons. The encoded protein is a type II transmembrane protein with a short cytoplasmic tail, a transmembrane domain, and a large extracellular domain where the enzymatic activity occurs.

Clinical significance

Alterations in the activity of Fucosyltransferase 4 have been associated with several diseases. Increased expression of the enzyme has been observed in certain types of cancer, including leukemia and breast cancer. In contrast, decreased activity has been linked to inflammatory bowel disease and rheumatoid arthritis.

See also

• Fucosyltransferase
• Glycosyltransferase
• Lewis antigen
• ABO blood group system