Linked Life Data

8543840

Source:http://linkedlifedata.com/resource/pubmed/id/8543840

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-2-14
pubmed:abstractText
Uncertainty exists over the site of processing of viral envelope (env) proteins for recognition by CTL. The extracellular domains of env proteins are not present in the cytosol, the site where the class I Ag processing pathway begins. Rather, the ecto-domains of env proteins are cotranslationally translocated into the endoplasmic reticulum during biosynthesis. To clarify the site of processing of viral env proteins, we examined the processing of an HLA B*3501-restricted epitope in the extracellular domain of the HIV-1 env protein. Although this epitope contains an N-linked glycosylation signal sequence, CTL specific for this epitope recognize a nonameric peptide that has not been previously modified by attachment of oligosaccharide. This was demonstrated in two ways. First, an env-specific B*3501-restricted CTL clone recognized a nonglycosylated, synthetic nonamer representing the minimal B*3501-restricted epitope, but not the glycosylated or deglycosylated forms. Second, the naturally processed, B*3501-restricted, env peptide is identical with a nonglycosylated, synthetic nonamer. Thus, the naturally processed form of an env epitope containing an N-linked glycosylation site is derived from env protein that is not glycosylated at the relevant asparagine during biosynthesis. Since the addition of N-linked oligosaccharides occurs only after the glycosylation signal sequence (N-X-S/T) is translocated into the endoplasmic reticulum, the initial processing reaction for this epitope may take place in the cytosol. Low-frequency failure of signal sequence containing polypeptides to engage the translocation apparatus, resulting in synthesis and degradation in the cytosol, may represent an important mechanism for the generation of class I-restricted CTL responses.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
156
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
834-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Class I-restricted presentation of an HIV-1 gp41 epitope containing an N-linked glycosylation site. Implications for the mechanism of processing of viral envelope proteins.
pubmed:affiliation
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't