| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-132 |
Sentence |
denotes |
EXTL2, a member of the EXT family of tumor suppressors, controls glycosaminoglycan biosynthesis in a xylose kinase-dependent manner. |
| T2 |
133-353 |
Sentence |
denotes |
Mutant alleles of EXT1 or EXT2, two members of the EXT gene family, are causative agents in hereditary multiple exostoses, and their gene products function together as a polymerase in the biosynthesis of heparan sulfate. |
| T3 |
354-600 |
Sentence |
denotes |
EXTL2, one of three EXT-like genes in the human genome that are homologous to EXT1 and EXT2, encodes a transferase that adds not only GlcNAc but also N-acetylgalactosamine to the glycosaminoglycan (GAG)-protein linkage region via an α1,4-linkage. |
| T4 |
601-717 |
Sentence |
denotes |
However, both the role of EXTL2 in the biosynthesis of GAGs and the biological significance of EXTL2 remain unclear. |
| T5 |
718-900 |
Sentence |
denotes |
Here we show that EXTL2 transfers a GlcNAc residue to the tetrasaccharide linkage region that is phosphorylated by a xylose kinase 1 (FAM20B) and thereby terminates chain elongation. |
| T6 |
901-1001 |
Sentence |
denotes |
We isolated an oligosaccharide from the mouse liver, which was not detected in EXTL2 knock-out mice. |
| T7 |
1002-1277 |
Sentence |
denotes |
Based on structural analysis by a combination of glycosidase digestion and 500-MHz (1)H NMR spectroscopy, the oligosaccharide was found to be GlcNAcα1-4GlcUAβ1-3Galβ1-3Galβ1-4Xyl(2-O-phosphate), which was considered to be a biosynthetic intermediate of an immature GAG chain. |
| T8 |
1278-1421 |
Sentence |
denotes |
Indeed, EXTL2 specifically transferred a GlcNAc residue to a phosphorylated linkage tetrasaccharide, GlcUAβ1-3Galβ1-3Galβ1-4Xyl(2-O-phosphate). |
| T9 |
1422-1579 |
Sentence |
denotes |
Remarkably, the phosphorylated linkage pentasaccharide generated by EXTL2 was not used as an acceptor for heparan sulfate or chondroitin sulfate polymerases. |
| T10 |
1580-1681 |
Sentence |
denotes |
Moreover, production of GAGs was significantly higher in EXTL2 knock-out mice than in wild-type mice. |
| T11 |
1682-1916 |
Sentence |
denotes |
These results indicate that EXTL2 functions to suppress GAG biosynthesis that is enhanced by a xylose kinase and that the EXTL2-dependent mechanism that regulates GAG biosynthesis might be a "quality control system" for proteoglycans. |
