کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1951002 | 1055731 | 2010 | 9 صفحه PDF | دانلود رایگان |
Calreticulin (CRT) is an important chaperone protein, comprising an N-domain, P-domain and C-domain. It is involved in the folding and assembly of multi-component protein complexes in the endoplasmic reticulum, and plays a critical role in MHC class I antigen processing and presentation. To dissect the functional role and molecular basis of individual domains of the protein, we have utilized individual domains to rescue impaired protein assembly in a CRT deficient cell line. Unexpectedly, both P-domain fragment and NP domain of CRT not only failed to rescue defective cell surface expression of MHC class I molecules but further inhibited their appearance on the surface of cells. Formation of the TAP-associated peptide-loading complex and trafficking of the few detectable MHC class I molecules were not significantly impaired. Instead, this further suppression of MHC class I molecules on the cell surface appears due to the complex missing antigenic peptides, the third member of fully assembled MHC class I molecules. Therefore the P-domain of calreticulin appears to play a significant role in antigen presentation by MHC class I molecules.
Journal: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research - Volume 1803, Issue 5, May 2010, Pages 544–552