EXT1:EXT2 transfers GlcNAc to the terminal GlcA residue

Stable Identifier
Reaction [transition]
Homo sapiens
The addition of GlcNAc to the terminal glucuronate residue starts heparan polymerization
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Exostosin1 and 2 (EXT1 and 2) are dual specificity enzymes which catalyze the addition of N acetylglucosamine (GlcNAc) and glucuronate (GlcA) to extend the GAG chain on the protein linker sequence. Heparan is synthesized once GlcNAc is transferred to this sequence. EXT1 and 2 form a heterodimer which translocates to the Golgi apparatus from the ER membrane (McCormick et al. 2000). Defects in EXT1 or 2 cause the hereditary bone disorders multiple exostoses type 1 (MIM:133700) and 2 (MIM:133701) (Wuyts et al. 1998, Bernard et al. 2001).
Literature References
PubMed ID Title Journal Year
10639137 The putative tumor suppressors EXT1 and EXT2 form a stable complex that accumulates in the Golgi apparatus and catalyzes the synthesis of heparan sulfate

Duncan, G, Goutsos, KT, Tufaro, F, McCormick, C

Proc Natl Acad Sci U S A 2000
9463333 Mutations in the EXT1 and EXT2 genes in hereditary multiple exostoses

Lüdecke, HJ, Willems, PJ, Hamel, B, Van Hul, W, Matsushita, M, Mollica, F, Bakker, E, Mortier, G, Conrad, EU, Wuyts, W, Hendrickx, J, Sayli, BS, Vanhoenacker, F, Raskind, WH, De Boulle, K, Pazzaglia, UE

Am J Hum Genet 1998
11169766 Diminished levels of the putative tumor suppressor proteins EXT1 and EXT2 in exostosis chondrocytes

Lüdecke, HJ, Hecht, JT, Cole, WG, Clines, GA, Van Winkle, WB, Scott, A, Hogue, DA, Hall, CE, Bernard, MA, Snuggs, MB, Lovett, M

Cell Motil Cytoskeleton 2001
Event Information
Catalyst Activity

glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-alpha-N-acetylglucosaminyltransferase activity of EXT1:EXT2 [Golgi membrane]

Orthologous Events
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