Linked Life Data

8765016

Source:http://linkedlifedata.com/resource/pubmed/id/8765016

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1996-10-24
pubmed:abstractText
The heterodimeric transporter associated with antigen processing (TAP1/TAP2) translocates peptides from the cytosol into the endoplasmic reticulum where loading of major histocompatibility complex class I molecules takes place. TAP transporters from different species are known to exhibit distinct transport specificities with regard to the C-terminal amino acid (aa) of peptides. Thus, human TAP (hTAP), and rat TAP (rTAP) containing the rTAP2a allele are rather promiscuous, whereas mouse TAP (mTAP), and rTAP containing the rTAP2a allele are restrictive and select against peptides with C-terminal small polar/hydrophobic or positively charged aa. The structural basis for this selectivity is not clear. To assess the relative contribution of the TAP1 and TAP2 subunits to transport specificity, we have constructed and analyzed interspecies TAP hybrids and point mutants of hTAP2 expressed in Sf9 insect cells and in TAP-deficient T2 cells. Transport assays with 20 C-terminal variants of the peptide RYWANATRSX showed that: first, transport specificity with regard to C-terminal aa is mainly influenced by TAP2, but TAP1 can also contribute. Second, the selective transport of peptides with C-terminal positively charged aa is critically controlled by the amino-terminal region (1-361) on the TAP2 chain, while transport of peptides with C-terminal small polar/hydrophobic aa is determined by residues located within as well as outside the region 1-361. Third, a single point mutation in hTAP2 (374A-->D) resulted in a drastic alteration of the transport pattern. These results indicate that both TAP1 and TAP2 contribute to efficient peptide transport and that single point mutations in hTAP2 are able to alter the peptide transport specificity. This opens the possibility that naturally occurring mutations in one of the hTAP subunits may alter epitope selection in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1748-55
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
A point mutation in the human transporter associated with antigen processing (TAP2) alters the peptide transport specificity.
pubmed:affiliation
Department of Molecular Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't