The V(D)J recombination process that assembles functional immunoglobulin and T cell receptor genes in lymphoid cells is essential for generating the diversity of the immune response. The reaction is now known to occur in two stages. In the first stage, specific double-strand breaks are made at the target sites. The ends of the coding DNA sequence at these breaks are always joined back on themselves as DNA hairpins. Based on cellular experiments, this unusual type of cleavage was known to utilize the products of the RAG1 and RAG2 genes, but it was not clear how they functioned. The later stages of recombination are less specific; the final joined products are made with the use of many factors also involved in the repair of radiation damage. We have now reproduced the first cleavage reaction in a biochemically defined reaction requiring only the purified RAG-1 and RAG-2 proteins. A DNA fragment containing the recognition signal sequence (RSS) is cut to make a hairpin coding end and a blunt signal end, just as in vivo. Furthermore, in more demanding reaction conditions, cleavage requires a pair of RSSs of the different types that are needed for recombination in vivo. Thus the RAG proteins alone contain all the information for the specificity of V(D)J recombination. We have also found that the hairpins are made in a reaction very similar chemically to transpositional recombination. An evolutionary relation between V(D)J recombination and transposable elements had previously been suggested, and our results provide the strongest data so far in support of this idea.
| Jones, Jessica M; Gellert, Martin (2004) The taming of a transposon: V(D)J recombination and the immune system. Immunol Rev 200:233-48 |
| Modesti, Mauro; Junop, Murray S; Ghirlando, Rodolfo et al. (2003) Tetramerization and DNA ligase IV interaction of the DNA double-strand break repair protein XRCC4 are mutually exclusive. J Mol Biol 334:215-28 |
| Jones, Jessica M; Gellert, Martin (2003) Autoubiquitylation of the V(D)J recombinase protein RAG1. Proc Natl Acad Sci U S A 100:15446-51 |
| Paull, T T; Cortez, D; Bowers, B et al. (2001) Direct DNA binding by Brca1. Proc Natl Acad Sci U S A 98:6086-91 |
| Jones, J M; Gellert, M (2001) Intermediates in V(D)J recombination: a stable RAG1/2 complex sequesters cleaved RSS ends. Proc Natl Acad Sci U S A 98:12926-31 |
| Jones, J M; Gellert, M; Yang, W (2001) A Ku bridge over broken DNA. Structure 9:881-4 |
| Paull, T T; Rogakou, E P; Yamazaki, V et al. (2000) A critical role for histone H2AX in recruitment of repair factors to nuclear foci after DNA damage. Curr Biol 10:886-95 |
| Paull, T T; Gellert, M (2000) A mechanistic basis for Mre11-directed DNA joining at microhomologies. Proc Natl Acad Sci U S A 97:6409-14 |
| Roth, D B; Gellert, M (2000) New guardians of the genome. Nature 404:823-5 |
| Junop, M S; Modesti, M; Guarne, A et al. (2000) Crystal structure of the Xrcc4 DNA repair protein and implications for end joining. EMBO J 19:5962-70 |
Showing the most recent 10 out of 11 publications
