Publication Date:
1994-01-21
Description:
Assembled class I histocompatibility molecules, consisting of heavy chain, beta 2-microglobulin, and peptide ligand, are transported rapidly to the cell surface. In contrast, the intracellular transport of free heavy chains or peptide-deficient heavy chain-beta 2-microglobulin heterodimers is impaired. A 90-kilodalton membrane-bound chaperone of the endoplasmic reticulum (ER), termed calnexin, associates quantitatively with newly synthesized class I heavy chains, but the functions of calnexin in this interaction are unknown. Class I subunits were expressed alone or in combination with calnexin in Drosophila melanogaster cells. Calnexin retarded the intracellular transport of both peptide-deficient heavy chain-beta 2-microglobulin heterodimers and free heavy chains. Calnexin also impeded the rapid intracellular degradation of free heavy chains. The ability of calnexin to protect and retain class I assembly intermediates is likely to contribute to the efficient intracellular formation of class I-peptide complexes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jackson, M R -- Cohen-Doyle, M F -- Peterson, P A -- Williams, D B -- New York, N.Y. -- Science. 1994 Jan 21;263(5145):384-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Immunology, Scripps Research Institute, La Jolla, CA 92037.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8278813" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Biological Transport
;
Calcium-Binding Proteins/*metabolism
;
Calnexin
;
Cell Line
;
Drosophila melanogaster
;
Endoplasmic Reticulum/*metabolism
;
Golgi Apparatus/metabolism
;
Histocompatibility Antigens Class I/*metabolism
;
Membrane Proteins/*metabolism
;
Molecular Sequence Data
;
Temperature
;
Transfection
;
beta 2-Microglobulin/*metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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