HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Leonhardt, R. M. Articles by Knittler, M. R. Search for Related Content PubMed PubMed Citation Articles by Leonhardt, R. M. Articles by Knittler, M. R. Pubmed/NCBI databases Gene GEO Profiles HomoloGene UniGene Substance via MeSH

Critical Role for the Tapasin-Docking Site of TAP2 in the Functional Integrity of the MHC Class I-Peptide-Loading Complex¹

University of Cologne, Institute for Genetics, Cologne, Germany

The transporter associated with Ag processing (TAP) translocates antigenic peptides into the endoplasmic reticulum for binding onto MHC class I (MHC I) molecules. Tapasin organizes a peptide-loading complex (PLC) by recruiting MHC I and accessory chaperones to the N-terminal regions (N domains) of the TAP subunits TAP1 and TAP2. To investigate the function of the tapasin-docking sites of TAP in MHC I processing, we expressed N-terminally truncated variants of TAP1 and TAP2 in combination with wild-type chains, as fusion proteins or as single subunits. Strikingly, TAP variants lacking the N domain in TAP2, but not in TAP1, build PLCs that fail to generate stable MHC I-peptide complexes. This correlates with a substantially reduced recruitment of accessory chaperones into the PLC demonstrating their important role in the quality control of MHC I loading. However, stable surface expression of MHC I can be rescued in post-endoplasmic reticulum compartments by a proprotein convertase-dependent mechanism.

This article has been cited by other articles:

				M. C. Verweij, D. Koppers-Lalic, S. Loch, F. Klauschies, H. de la Salle, E. Quinten, P. J. Lehner, A. Mulder, M. R. Knittler, R. Tampe, et al. The Varicellovirus UL49.5 Protein Blocks the Transporter Associated with Antigen Processing (TAP) by Inhibiting Essential Conformational Transitions in the 6+6 Transmembrane TAP Core Complex J. Immunol., October 1, 2008; 181(7): 4894 - 4907. [Abstract] [Full Text] [PDF]

				G. E. Dugan and E. W. Hewitt Structural and Functional Dissection of the Human Cytomegalovirus Immune Evasion Protein US6 J. Virol., April 1, 2008; 82(7): 3271 - 3282. [Abstract] [Full Text] [PDF]

				M. Marcilla, J. J. Cragnolini, and J. A. Lopez de Castro Proteasome-independent HLA-B27 Ligands Arise Mainly from Small Basic Proteins Mol. Cell. Proteomics, May 1, 2007; 6(5): 923 - 938. [Abstract] [Full Text] [PDF]

				M. Papadopoulos and F. Momburg Multiple Residues in the Transmembrane Helix and Connecting Peptide of Mouse Tapasin Stabilize the Transporter Associated with the Antigen-processing TAP2 Subunit J. Biol. Chem., March 30, 2007; 282(13): 9401 - 9410. [Abstract] [Full Text] [PDF]