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

J. Biol. Chem., Vol. 282, Issue 50, 36614-36625, December 14, 2007

This Article Full Text Full Text (PDF) All Versions of this Article: 282/50/36614    most recent M706324200v1 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 Google Scholar Google Scholar Articles by Young, K. A. Articles by Hannan, J. P. Search for Related Content PubMed PubMed Citation Articles by Young, K. A. Articles by Hannan, J. P. Social Bookmarking                      What's this?

Isolating the Epstein-Barr Virus gp350/220 Binding Site on Complement Receptor Type 2 (CR2/CD21)^*

Kendra A. Young, Xiaojiang S. Chen, V. Michael Holers, and Jonathan P. Hannan¹

From the Department of Medicine and Immunology, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045 and the Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089

Complement receptor type 2 (CR2/CD21) is essential for the attachment of Epstein-Barr virus (EBV) to the surface of B-lymphocytes in an interaction mediated by the viral envelope glycoprotein gp350. The heavily glycosylated structure of EBV gp350 has recently been elucidated by x-ray crystallography, and the CR2 binding site on this protein has been characterized. To identify the corresponding gp350 binding site on CR2, we have undertaken a site-directed mutagenesis study targeting regions of CR2 that have previously been implicated in the binding of CR2 to the C3d/C3dg fragments of complement component C3. Wild-type or mutant forms of CR2 were expressed on K562 cells, and the ability of these CR2-expressing cells to bind gp350 was measured using flow cytometry. Mutations directed toward the two N-terminal extracellular domains of CR2 (SCR1-2) reveal that a large contiguous surface of CR2 SCR1-2 is involved in gp350 binding, including a number of positively charged residues (Arg-13, (Arg-28, (Arg-36, Lys-41, Lys-57, Lys-67, and Arg-83). These data appear to complement the CR2 binding site on gp350, which is characterized by a preponderance of negative charge. In addition to identifying the importance of charge in the formation of a CR2-gp350 complex, we also provide evidence that both SCR1 and SCR2 make contact with gp350. Specifically, two anti-CR2 monoclonal antibodies, designated as monoclonal antibodies 171 and 1048 whose primary epitopes are located within SCR2, inhibit binding of wild-type CR2 to EBV gp350; with regard to SCR1, both K562 cells expressing an S15P mutation and recombinant S15P CR2 proteins exhibit diminished gp350 binding.

Received for publication, July 31, 2007 , and in revised form, October 9, 2007.

^* This work was supported by National Institutes of Health Grant R0-1 R01CA053615 (to V. M. H.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed: Division of Rheumatology, P. O. Box 6511, Mail Stop B-115, Dept. of Medicine and Immunology, Barbara Davis Center for Childhood Diabetes, University of Colorado at Denver and Health Sciences Center, 1775 N. Ursula St., Aurora, CO 80045. Tel.: 303-724-7605; Fax: 303-724-7581; E-mail: Jonathan.Hannan{at}UCHSC.edu.

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