| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-77 |
Sentence |
denotes |
Genes modulated by expression of GD3 synthase in Chinese hamster ovary cells. |
| T2 |
78-159 |
Sentence |
denotes |
Evidence that the Tis21 gene is involved in the induction of GD3 9-O-acetylation. |
| T3 |
160-292 |
Sentence |
denotes |
9-O-Acetylation is a common sialic acid modification, expressed in a developmentally regulated and tissue/cell type-specific manner. |
| T4 |
293-422 |
Sentence |
denotes |
The relevant 9-O-acetyltransferase(s) have not been isolated or cloned; nor have mechanisms for their regulation been elucidated. |
| T5 |
423-619 |
Sentence |
denotes |
We previously showed that transfection of the GD3 synthase (ST8Sia-I) gene into Chinese hamster ovary (CHO)-K1 cells gave expression of not only the disialoganglioside GD3 but also 9-O-acetyl-GD3. |
| T6 |
620-857 |
Sentence |
denotes |
We now use differential display PCR between wild type CHO-K1 cells and clones stably expressing GD3 synthase (CHO-GD3 cells) to detect any increased expression of other genes and explore the possible induction of a 9-O-acetyltransferase. |
| T7 |
858-1025 |
Sentence |
denotes |
The four CHO mRNAs showing major up-regulation were homologous to VCAM-1, Tis21, the KC-protein-like protein, and a functionally unknown type II transmembrane protein. |
| T8 |
1026-1102 |
Sentence |
denotes |
A moderate increase in expression of the FxC1 and SPR-1 genes was also seen. |
| T9 |
1103-1253 |
Sentence |
denotes |
Interestingly, these are different from genes observed by others to be up-regulated after transfection of GD3 synthase into a neuroblastoma cell line. |
| T10 |
1254-1359 |
Sentence |
denotes |
We also isolated a CHO-GD3 mutant lacking 9-O-acetyl-GD3 following chemical mutagenesis (CHO-GD3-OAc(-)). |
| T11 |
1360-1492 |
Sentence |
denotes |
Analysis of the above differential display PCR-derived genes in these cells showed that expression of Tis21 was selectively reduced. |
| T12 |
1493-1600 |
Sentence |
denotes |
Transfection of a mouse Tis21 cDNA into the CHO-GD3-OAc(-) mutant cells restored 9-O-acetyl-GD3 expression. |
| T13 |
1601-1848 |
Sentence |
denotes |
Since the only major gangliosides expressed by CHO-GD3 cells are GD3 and 9-O-acetyl-GD3 (in addition to GM3, the predominant ganglioside type in wild-type CHO-K1 cells), we conclude that GD3 enhances its own 9-O-acetylation via induction of Tis21. |
| T14 |
1849-2006 |
Sentence |
denotes |
This is the first known nuclear inducible factor for 9-O-acetylation and also the first proof that 9-O-acetylation can be directly regulated by GD3 synthase. |
| T15 |
2007-2175 |
Sentence |
denotes |
Finally, transfection of CHO-GD3-OAc(-) mutant cells with ST6Gal-I induced 9-O-acetylation specifically on sialylated N-glycans, in a manner similar to wild-type cells. |
| T16 |
2176-2329 |
Sentence |
denotes |
This indicates separate machineries for 9-O-acetylation on alpha2-8-linked sialic acids of gangliosides and on alpha2-6-linked sialic acids on N-glycans. |
