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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
30
|
| pubmed:dateCreated |
1991-12-2
|
| pubmed:abstractText |
Erythropoietin (Epo) has three N-linked sugar chains. Codons for asparagine at N-glycosylation sites in genomic human Epo DNA were replaced with those for glutamine. The wild-type Epo gene and seven mutants that lacked N-glycosylation sites in every possible combination were introduced into baby hamster-kidney cells. To study the role of the N-linked sugars in Epo biosynthesis, Epo protein expressed transiently was measured by an enzyme-linked immunoassay. The elimination of all three N-glycosylation sites decreased Epo production to 10% of that of the wild-type Epo. Wild-type and mutant Epos produced by stably transfected cells were partially purified to investigate their properties. Removal of N-glycosylation sites changed affinity of Epo to the receptor. The in vitro activity of Epo that lost all N-glycosylation sites was comparable with that of the wild-type Epo, while the in vivo activity severely decreased. These results indicate that N-linked sugars of Epo have two major functions; N-linked sugars are important for 1) proper biosynthesis and/or secretion and 2) expression of the in vivo activity probably by enhancing survival in the circulation. N-Linked sugars of Epo affect binding affinity of the ligand to the receptor but do not play a key role in expression of the in vitro activity.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
25
|
| pubmed:volume |
266
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
20434-9
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:1657925-Base Sequence,
pubmed-meshheading:1657925-Blotting, Western,
pubmed-meshheading:1657925-Cell Line,
pubmed-meshheading:1657925-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:1657925-Erythropoietin,
pubmed-meshheading:1657925-Glycosylation,
pubmed-meshheading:1657925-Humans,
pubmed-meshheading:1657925-Molecular Sequence Data,
pubmed-meshheading:1657925-Mutagenesis, Site-Directed,
pubmed-meshheading:1657925-Mutation,
pubmed-meshheading:1657925-Receptors, Cell Surface,
pubmed-meshheading:1657925-Receptors, Erythropoietin,
pubmed-meshheading:1657925-Transfection
|
| pubmed:year |
1991
|
| pubmed:articleTitle |
Effects of site-directed removal of N-glycosylation sites in human erythropoietin on its production and biological properties.
|
| pubmed:affiliation |
Research Institute of Life Science, Snow Brand Milk Products Co., Ltd., Tochigi, Japan.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|