biostudies-literatureDu HIntramural NIH HHSNIGMS NIH HHS641-9https://www.ebi.ac.uk/biostudies/studies/S-EPMC4589277biostudies-literatureUnknown31(5)Maintenance of genomic integrity during antigen receptor gene rearrangements requires (1) regulated access of the V(D)J recombinase to specific loci and (2) generation of double-strand DNA breaks only after recognition of a pair of matched recombination signal sequences (RSSs). Here we recapitulate both key aspects of regulated recombinase accessibility in a cell-free system using plasmid substrates assembled into chromatin. We show that recruitment of the SWI/SNF chromatin-remodeling complex to both RSSs increases coupled cleavage by RAG1 and RAG2 proteins. SWI/SNF functions by altering local chromatin structure in the absence of RNA polymerase II-dependent transcription or histone modifications. These observations demonstrate a direct role for cis-sequence-regulated local chromatin remodMolecular cellActivation of 12/23-RSS-dependent RAG cleavage by hSWI/SNF complex in the absence of transcription.PMC4589277R01 GM038925ZIA AG000374-03GM38925Z01 AG000524-03Du HIshii HPazin MJSen RfalseActivation of 12/23-RSS-dependent RAG cleavage by hSWI/SNF complex in the absence of transcription.Maintenance of genomic integrity during antigen receptor gene rearrangements requires (1) regulated access of the V(D)J recombinase to specific loci and (2) generation of double-strand DNA breaks only after recognition of a pair of matched recombination signal sequences (RSSs). Here we recapitulate both key aspects of regulated recombinase accessibility in a cell-free system using plasmid substrates assembled into chromatin. We show that recruitment of the SWI/SNF chromatin-remodeling complex to both RSSs increases coupled cleavage by RAG1 and RAG2 proteins. SWI/SNF functions by altering local chromatin structure in the absence of RNA polymerase II-dependent transcription or histone modifications. These observations demonstrate a direct role for cis-sequence-regulated local chromatin remod2008-01-01T00:00:00Z2008 Sep2025-06-01T12:01:39.208Z2025-06-01T12:01:39.208ZS-EPMC45892771877532410.1016/j.molcel.2008.08.012