| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-179 |
Sentence |
denotes |
Insights into O-linked N-acetylglucosamine ([0-9]O-GlcNAc) processing and dynamics through kinetic analysis of O-GlcNAc transferase and O-GlcNAcase activity on protein substrates. |
| T2 |
180-361 |
Sentence |
denotes |
Cellular O-linked N-acetylglucosamine (O-GlcNAc) levels are modulated by two enzymes: uridine diphosphate-N-acetyl-D-glucosamine:polypeptidyltransferase (OGT) and O-GlcNAcase (OGA). |
| T3 |
362-537 |
Sentence |
denotes |
To quantitatively address the activity of these enzymes on protein substrates, we generated five structurally diverse proteins in both unmodified and O-GlcNAc-modified states. |
| T4 |
538-776 |
Sentence |
denotes |
We found a remarkably invariant upper limit for k(cat)/K(m) values for human OGA (hOGA)-catalyzed processing of these modified proteins, which suggests that hOGA processing is driven by the GlcNAc moiety and is independent of the protein. |
| T5 |
777-923 |
Sentence |
denotes |
Human OGT (hOGT) activity ranged more widely, by up to 15-fold, suggesting that hOGT is the senior partner in fine tuning protein O-GlcNAc levels. |
| T6 |
924-1189 |
Sentence |
denotes |
This was supported by the observation that K(m,app) values for UDP-GlcNAc varied considerably (from 1 μM to over 20 μM), depending on the protein substrate, suggesting that some OGT substrates will be nutrient-responsive, whereas others are constitutively modified. |
| T7 |
1190-1478 |
Sentence |
denotes |
The ratios of k(cat)/K(m) values obtained from hOGT and hOGA kinetic studies enable a prediction of the dynamic equilibrium position of O-GlcNAc levels that can be recapitulated in vitro and suggest the relative O-GlcNAc stoichiometries of target proteins in the absence of other factors. |
| T8 |
1479-1735 |
Sentence |
denotes |
We show that changes in the specific activities of hOGT and hOGA measured in vitro on calcium/calmodulin-dependent kinase IV (CaMKIV) and its pseudophosphorylated form can account for previously reported changes in CaMKIV O-GlcNAc levels observed in cells. |
| T9 |
1736-1935 |
Sentence |
denotes |
These studies provide kinetic evidence for the interplay between O-GlcNAc and phosphorylation on proteins and indicate that these effects can be mediated by changes in hOGT and hOGA kinetic activity. |
