Antigen receptor gene rearrangement is directed by DNA motifs consisting of a conserved heptamer and nonamer separated by a nonconserved spacer of either 12 or 23 base pairs (12 or 23 recombination signal sequences [RSS]). V(D)J recombination requires that the rearranging DNA segments be flanked by RSSs of different spacer lengths, a phenomenon known as the 12/23 rule. Recent studies have shown that this restriction operates at the level of DNA cleavage, which is mediated by the products of the recombination activating genes RAG1 and RAG2. Here, we show that RAG1 and RAG2 are not sufficient for 12/23 dependent cleavage, whereas RAG1 and RAG2 complemented with whole cell extract faithfully recapitulates the 12/23 rule. In addition, HMG box containing proteins HMG1 and HMG2 enhance RAG1- and RAG2-mediated cleavage of substrates containing 23 RSS but not of substrates containing only 12 RSS. These results suggest the existence of a nucleoprotein complex at the cleavage site, consisting of architectural, catalytic, and regulatory components.
V(D)J Recombination: Modulation of RAG1 and RAG2 Cleavage Activity on 12/23 Substrates by Whole Cell Extract and DNA-bending Proteins
Address correspondence to Patricia Cortes, Laboratory of Molecular Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10021.
D.J. Sawchuk is supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) PGS-A fellowship. M.C. Nussenzweig is an associate investigator of the Howard Hughes Medical Institute. This work was supported in part by grants from the National Institutes of Health to M.C. Nussenzweig.
1Abbreviations used in this paper: HMG, high mobility group protein; IHF, integration host factor; RSS, recombination signal sequences; WCE, whole cell extract.
Dennis J. Sawchuk, Frances Weis-Garcia, Sohail Malik, Eva Besmer, Michael Bustin, Michel C. Nussenzweig, Patricia Cortes; V(D)J Recombination: Modulation of RAG1 and RAG2 Cleavage Activity on 12/23 Substrates by Whole Cell Extract and DNA-bending Proteins. J Exp Med 2 June 1997; 185 (11): 2025–2032. doi: https://doi.org/10.1084/jem.185.11.2025
Download citation file:
Sign in
Client Account
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement