Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2001-4-17
pubmed:abstractText
Invariant chain (Ii) serves as a chaperone for folding and intracellular transport of major histocompatibility complex class II (MHCII) molecules. Early in biosynthesis, Ii associates with MHCII molecules and directs their intracellular transport to endocytic compartments where vesicular proteinases sequentially release Ii from the MHCII heterodimer. The detachment of Ii makes the MHCII groove susceptible for binding of antigenic peptides. We investigated the role of N-linked glycosylation in the controlled intracellular degradation of Ii. Motifs for asparagine-linked glycosylation were altered, and mutated Ii (IiNmut) was transiently expressed in COS cells. The half-life of IiNmut was strongly reduced compared with wild-type Ii although the sensitivity of the N glycan-free polypeptide to in vitro proteinase digestion was not substantially increased. Inhibition of vesicular proteinases revealed endosomal degradation of IiNmut. Intracellular proteolysis of IiNmut is substantially impaired by serine proteinase inhibitors. Thus, a considerable amount of IiNmut is degraded in nonacidic intracellular compartments. The data suggest that N-linked glycosylation of Ii hinders premature proteolysis in nonacidic vesicles resulting in Ii degradation in acidic MHC class II-processing compartments.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13469-75
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:11278714-Amino Acid Sequence, pubmed-meshheading:11278714-Animals, pubmed-meshheading:11278714-Antibodies, Monoclonal, pubmed-meshheading:11278714-Asparagine, pubmed-meshheading:11278714-Base Sequence, pubmed-meshheading:11278714-Binding Sites, pubmed-meshheading:11278714-Binding Sites, Antibody, pubmed-meshheading:11278714-Biotinylation, pubmed-meshheading:11278714-COS Cells, pubmed-meshheading:11278714-Cercopithecus aethiops, pubmed-meshheading:11278714-Cross-Linking Reagents, pubmed-meshheading:11278714-Endopeptidases, pubmed-meshheading:11278714-Glycosylation, pubmed-meshheading:11278714-Histocompatibility Antigens Class II, pubmed-meshheading:11278714-Kinetics, pubmed-meshheading:11278714-Macromolecular Substances, pubmed-meshheading:11278714-Mice, pubmed-meshheading:11278714-Mutagenesis, Site-Directed, pubmed-meshheading:11278714-Rats, pubmed-meshheading:11278714-Recombinant Proteins, pubmed-meshheading:11278714-Transfection
pubmed:year
2001
pubmed:articleTitle
Glycosylation signals that separate the trimerization from the mhc class II-binding domain control intracellular degradation of invariant chain.
pubmed:affiliation
Section of Immunobiology, University of Bonn, 53117 Bonn, Römerstrasse 164, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't