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==Structural features underlying T-cell receptor sensitivity to concealed MHC class I micropolymorphisms== | |||
<StructureSection load='2ypk' size='340' side='right' caption='[[2ypk]], [[Resolution|resolution]] 1.95Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2ypk]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2YPK OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2YPK FirstGlance]. <br> | |||
==Disease== | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2ypl|2ypl]]</td></tr> | ||
[[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:[http://omim.org/entry/241600 241600]]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.<ref>PMID:16549777</ref> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ypk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ypk OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2ypk RCSB], [http://www.ebi.ac.uk/pdbsum/2ypk PDBsum]</span></td></tr> | ||
</table> | |||
== Disease == | |||
[[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:[http://omim.org/entry/241600 241600]]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.<ref>PMID:16549777</ref> Note=Beta-2-microglobulin may adopt the fibrillar configuration of amyloid in certain pathologic states. The capacity to assemble into amyloid fibrils is concentration dependent. Persistently high beta(2)-microglobulin serum levels lead to amyloidosis in patients on long-term hemodialysis.<ref>PMID:3532124</ref> <ref>PMID:1336137</ref> <ref>PMID:7554280</ref> <ref>PMID:4586824</ref> <ref>PMID:8084451</ref> <ref>PMID:12119416</ref> <ref>PMID:12796775</ref> <ref>PMID:16901902</ref> <ref>PMID:16491088</ref> <ref>PMID:17646174</ref> <ref>PMID:18835253</ref> <ref>PMID:18395224</ref> <ref>PMID:19284997</ref> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/1B57_HUMAN 1B57_HUMAN]] Involved in the presentation of foreign antigens to the immune system. [[http://www.uniprot.org/uniprot/Q70XD7_9HIV1 Q70XD7_9HIV1]] Gag-Pol polyprotein and Gag polyprotein may regulate their own translation, by the binding genomic RNA in the 5'-UTR. At low concentration, Gag-Pol and Gag would promote translation, whereas at high concentration, the polyproteins encapsidate genomic RNA and then shutt off translation (By similarity).[SAAS:SAAS012344_004_047815] Nucleocapsid protein p7 encapsulates and protects viral dimeric unspliced (genomic) RNA. Binds these RNAs through its zinc fingers. Facilitates rearangement of nucleic acid secondary structure during retrotranscription of genomic RNA. This capability is referred to as nucleic acid chaperone activity (By similarity).[SAAS:SAAS012344_004_052592] [[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Polymorphic differences distinguishing MHC class I subtypes often permit the presentation of shared epitopes in conformationally identical formats but can affect T-cell repertoire selection, differentially impacting autoimmune susceptibilities and viral clearance in vivo. The molecular mechanisms underlying this effect are not well understood. We performed structural, thermodynamic, and functional analyses of a conserved T-cell receptor (TCR) which is frequently expanded in response to a HIV-1 epitope when presented by HLA-B*5701 but is not selected by HLA-B*5703, which differs from HLA-B*5701 by two concealed polymorphisms. Our findings illustrate that although both HLA-B*57 subtypes display the epitope in structurally conserved formats, the impact of their polymorphic differences occurs directly as a consequence of TCR ligation, primarily because of peptide adjustments required for TCR binding, which involves the interplay of polymorphic residues and water molecules. These minor differences culminate in subtype-specific differential TCR-binding kinetics and cellular function. Our data demonstrate a potential mechanism whereby the most subtle MHC class I micropolymorphisms can influence TCR use and highlight their implications for disease outcomes. | |||
Structural features underlying T-cell receptor sensitivity to concealed MHC class I micropolymorphisms.,Stewart-Jones GB, Simpson P, van der Merwe PA, Easterbrook P, McMichael AJ, Rowland-Jones SL, Jones EY, Gillespie GM Proc Natl Acad Sci U S A. 2012 Dec 11;109(50):E3483-92. doi:, 10.1073/pnas.1207896109. Epub 2012 Nov 16. PMID:23161907<ref>PMID:23161907</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Beta-2 microglobulin|Beta-2 microglobulin]] | *[[Beta-2 microglobulin|Beta-2 microglobulin]] | ||
== References == | |||
== | <references/> | ||
<references | __TOC__ | ||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Easterbrook, P | [[Category: Easterbrook, P]] | ||
[[Category: Gillespie, G M | [[Category: Gillespie, G M]] | ||
[[Category: Jones, E Y | [[Category: Jones, E Y]] | ||
[[Category: Mcmichael, A J | [[Category: Mcmichael, A J]] | ||
[[Category: Merwe, P A.Van Der | [[Category: Merwe, P A.Van Der]] | ||
[[Category: Rowland-Jones, S L | [[Category: Rowland-Jones, S L]] | ||
[[Category: Simpson, P | [[Category: Simpson, P]] | ||
[[Category: Stewart-Jones, G B | [[Category: Stewart-Jones, G B]] | ||
[[Category: Immune system]] | [[Category: Immune system]] | ||
[[Category: Micropolymorphism]] | [[Category: Micropolymorphism]] |