| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-67 |
Sentence |
denotes |
Effect of alternative glycosylation on insulin receptor processing. |
| T2 |
68-189 |
Sentence |
denotes |
The mature insulin receptor is a cell surface heterotetrameric glycoprotein composed of two alpha- and two beta-subunits. |
| T3 |
190-373 |
Sentence |
denotes |
In 3T3-L1 adipocytes as in other cell types, the receptor is synthesized as a single polypeptide consisting of uncleaved alpha- and beta-subunits, migrating as a 190-kDa glycoprotein. |
| T4 |
374-532 |
Sentence |
denotes |
To examine the importance of N-linked glycosylation on insulin receptor processing, we have used glucose deprivation as a tool to alter protein glycosylation. |
| T5 |
533-741 |
Sentence |
denotes |
Western blot analysis shows that glucose deprivation led to a time-dependent accumulation of an alternative proreceptor of 170 kDa in a subcellular fraction consistent with endoplasmic reticulum localization. |
| T6 |
742-874 |
Sentence |
denotes |
Co-precipitation assays provide evidence that the alternative proreceptor bound GRP78, an endoplasmic reticulum molecular chaperone. |
| T7 |
875-976 |
Sentence |
denotes |
N-Glycosidase F treatment shows that the alternative proreceptor contained N-linked oligosaccharides. |
| T8 |
977-1062 |
Sentence |
denotes |
Yet, endoglycosidase H insensitivity indicates an aberrant oligosaccharide structure. |
| T9 |
1063-1185 |
Sentence |
denotes |
Using pulse-chase methodology, we show that the synthetic rate was similar between the normal and alternative proreceptor. |
| T10 |
1186-1368 |
Sentence |
denotes |
However, the normal proreceptor was processed into alpha- and beta-subunits (t((1)/(2)) = 1.3 +/- 0.6 h), while the alternative proreceptor was degraded (t((1)/(2)) = 5.1 +/- 0.6 h). |
| T11 |
1369-1551 |
Sentence |
denotes |
Upon refeeding cells that were initially deprived of glucose, the alternative proreceptor was processed to a higher molecular weight form and gained sensitivity to endoglycosidase H. |
| T12 |
1552-1716 |
Sentence |
denotes |
This "intermediate" form of the proreceptor was also degraded, although a small fraction escaped degradation, resulting in cleavage to the alpha- and beta-subunits. |
| T13 |
1717-1977 |
Sentence |
denotes |
These data provide evidence for the first time that glucose deprivation leads to the accumulation of an alternative proreceptor, which can be post-translationally glycosylated with the readdition of glucose inducing both accelerated degradation and maturation. |
