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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3
|
| pubmed:dateCreated |
1987-4-1
|
| pubmed:abstractText |
The insulin receptor is synthesized as a 190,000-Mr single-chain precursor that contains exclusively asparagine-N-linked high-mannose-type carbohydrate chains. In this study we have characterized the structure of the pro-receptor oligosaccharides. IM-9 lymphocytes were pulse-chase-labelled with [3H]mannose, and the insulin pro-receptor was isolated by immunoprecipitation and SDS/polyacrylamide-gel electrophoresis. The pro-receptor oligosaccharides were removed from the protein backbone with endoglycosidase H and analysed by h.p.l.c. Immediately after a [3H]mannose pulse the largest oligosaccharide found in the pro-receptor was Glc1Man9GlcNAc2; this structure represented only a small fraction (3%) of the total. The predominant oligosaccharides present in the pro-receptor were Man9GlcNAc2 (25%) and Man8GlcNAc2 (48%). Smaller oligosaccharides were also detected: Man7GlcNAc2 (18%), Man6GlcNAc2 (3%) and Man5GlcNAc2 (3%). The relative distribution of the different oligosaccharides did not change at 1, 2 or 3 h after the pulse with the exception of the rapid disappearance of the Glc1Man9GlcNAc2 component. The mature alpha- and beta-subunits of the insulin receptor are known to contain both high-mannose-type and complex-type oligosaccharides. We have also examined here the structure of the high-mannose chains of these subunits. The predominant species in the alpha-subunit was Man8GlcNAc2 whereas in the beta-subunit it was Man7GlcNAc2. These results demonstrate that most (approx. 75%) oligosaccharides of the insulin pro-receptor are chains of the type Man8GlcNAc2 or Man9GlcNAc2. Thus, assuming that a Glc3Man9GlcNAc2 species is transferred co-translationally, carbohydrate processing of the pro-receptor appears to be very rapid and limited to the removal of the three glucose residues and one mannose residue. Further mannose removal does not occur until the pro-receptor has been proteolytically cleaved. In addition, the degree of mannose trimming appears to be different in the alpha- and beta-subunits.
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| pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-1159895,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-220252,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-2983222,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-3905553,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-3936487,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-4077982,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-434842,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6100148,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6258482,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6368559,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6411700,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6669046,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-6946427,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-7023366,
http://linkedlifedata.com/resource/pubmed/commentcorrection/3827820-7240203
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0264-6021
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
239
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
679-83
|
| pubmed:dateRevised |
2009-11-19
|
| pubmed:meshHeading | |
| pubmed:year |
1986
|
| pubmed:articleTitle |
Characterization of the N-linked high-mannose oligosaccharides of the insulin pro-receptor and mature insulin receptor subunits.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|