title: Chromatin dynamics during DNA repair revealed by pair correlation analysis of molecular flow in the nucleus.
abstract: Chromatin dynamics modulate DNA repair factor accessibility throughout the DNA damage response. The spatiotemporal scale upon which these dynamics occur render them invisible to live cell imaging. Here we present a believed novel assay to monitor the in vivo structural rearrangements of chromatin during DNA repair. By pair correlation analysis of EGFP molecular flow into chromatin before and after damage, this assay measures millisecond variations in chromatin compaction with submicron resolution. Combined with laser microirradiation we employ this assay to monitor the real-time accessibility of DNA at the damage site. We find from comparison of EGFP molecular flow with a molecule that has an affinity toward double-strand breaks (Ku-EGFP) that DNA damage induces a transient decrease in chromatin compaction at the damage site and an increase in compaction to adjacent regions, which together facilitate DNA repair factor recruitment to the lesion with high spatiotemporal control.
authors.affiliation: Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California; School of Medical Sciences and Australian Centre for NanoMedicine, University of New South Wales, Sydney, Australia. Electronic address: e.hinde@unsw.edu.au.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hinde
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, California.
authors.forename: Xiangduo
authors.initials: X
authors.lastname: Kong
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Irvine, California. Electronic address: kyokomor@uci.edu.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yokomori
authors.affiliation: Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California.
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
mesh_terms: D002467:Cell Nucleus / Q000235:genetics*; D002843:Chromatin / Q000737:chemistry / Q000235:genetics*; D053903:DNA Breaks, Double-Stranded; D006367:HeLa Cells; D006801:Humans; D059767:Recombinational DNA Repair
chemical_list: D002843:Chromatin