EXT1 : exostosin glycosyltransferase 1
Description
The EXT1 (exostosin glycosyltransferase 1) is a protein-coding gene located on chromosome 8.
The EXT1 gene instructs the production of exostosin-1, a protein found in the Golgi apparatus. Here, it binds to exostosin-2, forming a complex that modifies heparan sulfate. Heparan sulfate is a polysaccharide that attaches to proteins to form proteoglycans, regulating various processes including blood clotting, blood vessel formation, and cancer cell metastasis.
EXT1, along with EXT2, forms a heterodimeric complex called heparan sulfate polymerase. This polymerase is crucial for elongating the heparan sulfate glycan backbone by alternatingly adding (1->4)-beta-D-GlcA and (1->4)-alpha-D-GlcNAc residues from their respective UDP-sugar donors. EXT1 specifically carries the N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity within the complex, while EXT2 contributes the glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity. Heparan sulfate proteoglycans, ubiquitous components of the extracellular matrix, are essential for tissue homeostasis and signaling.
EXT1 is also known as EXT, LGCR, LGS, TRPS2, TTV.
Associated Diseases
- Exostoses, multiple, type I
- Multiple osteochondromas
- Trichorhinophalangeal syndrome type 2
- Chondrosarcoma
- Hereditary multiple osteochondromas
- Trichorhinophalangeal syndrome type II
