EXT1:EXT2 transfers GlcA to heparan

Stable Identifier
Reaction [transition]
Homo sapiens
Another GlcA addition extends the heparan chain
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Exostosin 1 and 2 (EXT1 and 2) are dual specificity enzymes which catalyze the addition of N-acetylglucosamine (GlcNAc) and glucuronate (GlcA) to the GAG protein linker sequence. The first addition mediated by these enzymes is that of glucuronate after EXTL1 has added the first GlcNAc unit to the linkage 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
Catalyst Activity

N-acetylglucosaminyl-proteoglycan 4-beta-glucuronosyltransferase activity of EXT1:EXT2 [Golgi membrane]

Orthologous Events
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