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 Email this article to a friend 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 Ben-Shahar, S. Articles by Reiss, Y. Search for Related Content PubMed PubMed Citation Articles by Ben-Shahar, S. Articles by Reiss, Y. Social Bookmarking                      What's this?

Volume 272, Number 34, Issue of August 22, 1997 pp. 21060-21066
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

Production of a Specific Major Histocompatibility Complex Class I-restricted Epitope by Ubiquitin-dependent Degradation of Modified Ovalbumin in Lymphocyte Lysate

(Received for publication, April 3, 1997, and in revised form, May 30, 1997)

Sary Ben-Shahar , Bosmat Cassouto , Lion Novak , Angel Porgador ^§ and Yuval Reiss

From the  Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel and the ^§ Lymphocyte Biology Section, Laboratory of Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892-1892

Peptide epitopes presented through class I major histocompatability complex (MHC class I) on the cell surface, are generated by proteolytic processing of protein-antigens in the cytoplasm. The length and amino acid sequence determine whether a given peptide can fit into the peptide binding groove of class I heavy chain molecules and subsequently be presented to the immune system. The mode of action of the processing pathway is therefore of great interest. To study the processing mechanism of MHC class I-restricted intracellular antigens, we reconstituted the proteolytic processing of a model antigen in a cell-free system. Incubation of oxidized and urea-treated OVA in lymphocyte lysate resulted in partial degradation of the antigen. Degradation of the antigen depended on the presence of ATP. Addition of methylated ubiquitin abolished the reaction which was then restored by addition of an excess of native ubiquitin, indicating that the breakdown of the antigen in lymphocyte lysate is mediated by the ubiquitin proteolytic system. Upon incubation of modified OVA in lymphocyte lysate, a specific antigenic peptide was generated. The peptide was recognized by cytotoxic T lymphocytes directed against OVA-derived, H-2K^b-restricted peptide (SIINFEKL), and by a monoclonal antibody that recognizes cell-bound K^b-SIINFEKL complexes. Formation of the peptide epitope depended on the presence of ATP and ubiquitin. These results indicate that proteolytic processing of modified OVA is carried out by the ubiquitin-mediated degradation system. The experimental system described provides a tool to analyze the molecular mechanisms underlying the generation of specific, MHC class I-restricted peptide epitopes.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				W. M. Cohen, A. Bianco, F. Connan, L. Camoin, M. Dalod, G. Lauvau, E. Ferries, B. Culmann-Penciolelli, P. M. van Endert, J. P. Briand, et al. Study of Antigen-Processing Steps Reveals Preferences Explaining Differential Biological Outcomes of Two HLA-A2-Restricted Immunodominant Epitopes from Human Immunodeficiency Virus Type 1 J. Virol., September 11, 2002; 76(20): 10219 - 10225. [Abstract] [Full Text] [PDF]

				S. Ben-Shahar, A. Komlosh, E. Nadav, I. Shaked, T. Ziv, A. Admon, G. N. DeMartino, and Y. Reiss 26 S Proteasome-mediated Production of an Authentic Major Histocompatibility Class I-restricted Epitope from an Intact Protein Substrate J. Biol. Chem., July 30, 1999; 274(31): 21963 - 21972. [Abstract] [Full Text] [PDF]

				N. P. N. Emmerich, A. K. Nussbaum, S. Stevanovic, M. Priemer, R. E. M. Toes, H.-G. Rammensee, and H. Schild The Human 26 S and 20 S Proteasomes Generate Overlapping but Different Sets of Peptide Fragments from a Model Protein Substrate J. Biol. Chem., July 7, 2000; 275(28): 21140 - 21148. [Abstract] [Full Text] [PDF]

				A. Komlosh, F. Momburg, T. Weinschenk, N. Emmerich, H. Schild, E. Nadav, I. Shaked, and Y. Reiss A Role for a Novel Luminal Endoplasmic Reticulum Aminopeptidase in Final Trimming of 26 S Proteasome-generated Major Histocompatability Complex Class I Antigenic Peptides J. Biol. Chem., August 3, 2001; 276(32): 30050 - 30056. [Abstract] [Full Text] [PDF]