title: Single-strand recombination signal sequence nicks in vivo: evidence for a capture model of synapsis.
abstract: Variable (diversity) joining (V(D)J) recombination is initiated by the introduction of single-strand DNA breaks (nicks) at recombination signal sequences (RSSs). The importance and fate of these RSS nicks for the regulation of the V(D)J rearrangement and their potential contribution to genomic instability are poorly understood. Using two new methodologies, we were able to detect and quantify specific RSS nicks introduced into genomic DNA by incubation with recombination-activating gene proteins in vitro. In vivo, however, we found that nicks mediated by recombination-activating gene (RAG) proteins were detectable only in gene segments associated with RSSs containing 12-base pair spacers but not in those containing 23-base pair spacers. These data support a model of capture rather than synapsis for pairwise RSS cleavage during V(D)J recombination.
authors.affiliation: Department of Molecular and Cell Biology, Division of Immunology, University of California, Berkeley, California 94720-3200, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Curry
authors.forename: Jamie K
authors.initials: JK
authors.lastname: Geier
authors.forename: Mark S
authors.initials: MS
authors.lastname: Schlissel
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D023902:Chromosome Pairing / Q000502:physiology*; D004247:DNA / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D015321:Gene Rearrangement / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008957:Models, Genetic; D011995:Recombination, Genetic / Q000502:physiology; D045567:VDJ Recombinases / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; C499308:Rag2 protein, mouse; D004247:DNA; D045567:VDJ Recombinases