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

J. Biol. Chem., Vol. 279, Issue 44, 46213-46225, October 29, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/44/46213    most recent M406280200v1 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 Raghavan, S. C. Articles by Lieber, M. R. Search for Related Content PubMed PubMed Citation Articles by Raghavan, S. C. Articles by Lieber, M. R. Social Bookmarking                      What's this?

Stability and Strand Asymmetry in the Non-B DNA Structure at the bcl-2 Major Breakpoint Region^*

Sathees C. Raghavan¶||**, Sabrina Houston¶||**, Balachandra G. Hegde, Ralf Langen, Ian S. Haworth¶, and Michael R. Lieber¶||**¶¶

From the Norris Comprehensive Cancer Center, the Departments of Pathology, ^¶Biochemistry and Molecular Biology, ^||Biological Sciences, ^**Molecular Microbiology and Immunology, and Pharmaceutical Sciences, and the Zilka Neurogenetics Institute, University of Southern California Keck School of Medicine, Los Angeles, California 90033

The t(14;18) translocation involving the Ig heavy chain locus and the BCL-2 gene is the single most common chromosomal translocation in human cancer. Recently we reported in vitro and in vivo chemical probing data indicating that the 150-bp major breakpoint region (Mbr), which contains three breakage subregions (hotspots) (known as peaks I, II, and III), has single-stranded character and hence a non-B DNA conformation. Although we could document the non-B DNA structure formation at the bcl-2 Mbr, the structural studies were limited to chemical probing. Therefore, in the present study, we used multiple methods including circular dichroism to detect the non-B DNA at the bcl-2 Mbr. We established a new gel shift method to detect the altered structure at neutral pH on shorter DNA fragments containing the bcl-2 Mbr and analyzed the fine structural features. We found that the single-stranded region in the non-B DNA structure observed is stable for days and is asymmetric with respect to the Watson and Crick strands. It could be detected by oligomer probing, a bisulfite modification assay, or a P1 nuclease assay. We provide evidence that two different non-B conformations exist at peak I in addition to the single one observed at peak III. Finally we used mutagenesis and base analogue incorporation to show that the non-B DNA structure formation requires Hoogsteen pairing. These findings place major constraints on the location and nature of the non-B conformations assumed at peaks I and III of the bcl-2 Mbr.

Received for publication, June 7, 2004 , and in revised form, July 29, 2004.

^* This work was supported by National Institutes of Health grants. 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.

^¶¶ To whom correspondence should be addressed: Norris Comprehensive Cancer Center, Rm. 5428, University of Southern California Keck School of Medicine, 1441 Eastlake Ave., MC9176, Los Angeles, CA 90033. Tel.: 323-865-0568; Fax: 323-865-3019; E-mail: lieber{at}usc.edu.

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

This article has been cited by other articles:

				S. C. Raghavan, C.-L. Hsieh, and M. R. Lieber Both V(D)J Coding Ends but Neither Signal End Can Recombine at the bcl-2 Major Breakpoint Region, and the Rejoining Is Ligase IV Dependent Mol. Cell. Biol., August 1, 2005; 25(15): 6475 - 6484. [Abstract] [Full Text] [PDF]

				S. C. Raghavan, P. C. Swanson, Y. Ma, and M. R. Lieber Double-Strand Break Formation by the RAG Complex at the Bcl-2 Major Breakpoint Region and at Other Non-B DNA Structures In Vitro Mol. Cell. Biol., July 15, 2005; 25(14): 5904 - 5919. [Abstract] [Full Text] [PDF]

				S. C. Raghavan, P. Chastain, J. S. Lee, B. G. Hegde, S. Houston, R. Langen, C.-L. Hsieh, I. S. Haworth, and M. R. Lieber Evidence for a Triplex DNA Conformation at the bcl-2 Major Breakpoint Region of the t(14;18) Translocation J. Biol. Chem., June 17, 2005; 280(24): 22749 - 22760. [Abstract] [Full Text] [PDF]