Role of chromatin dynamics during the DNA damage response

Researcher

Project Details

Tumour suppression relies on the preservation of genome integrity and this is maintained by a cellular surveillance system called the DNA damage response (DDR). Amazingly the DDR can almost instantaneously detect a genomic lesion. However, how it spatiotemporally coordinates DNA repair factor recruitment to that damage site is not currently understood. We recently demonstrated that double-strand breaks (DSB) induce a transient local ‘opening’ of chromatin at the damage site that is bordered by an increased level of chromatin compaction (Hinde et al. 2014 Biophys. J 107(1)). These dynamic rearrangements in local DNA density appear to facilitate DNA repair factor accumulation at only the damage site. The overall aim of this project is to investigate how these changes in chromatin compaction modulate genome topology to facilitate the DDR. By use of a fluorescence lifetime imaging microscopy (FLIM) based assay, we will test the hypothesis that spatial heterogeneity in chromatin compaction during the DDR serves to facilitate DNA repair factor access whilst blocking transcription of neighbouring genes.

Pair correlation analysis of EGFP access into the chromatin network
Figure 1: Pair correlation analysis of EGFP access throughout the chromatin network found the DNA damage respone to induce an ‘opening’ of chromatin at a damage site and ‘closing’ of the borders surrounding the lesion. (b)-(c). FRET between fluorescently labelled H2B histones (b) can be used as a read out of chromatin compaction (c). (d) FRET maps of chromatin organisation during the DNA damage response with pixel level resolution. Green to red pixels (high to low fluorescence lifetime due to increasing FRET) indicate a low to high level of chromatin compaction. Black box indicates the induced DNA damage site.

Researchers

Jieqiong Lou, Post doctoral researcher

Jee Khor, Honours research student

Collaborators

Dr Tony Cesare, Childrens Medical Research Institute, Sydney, Australia

Professor Enrico Gratton, University of California, Irvine, USA

Funding

NHMRC Project Grant (2016-2019) 'The role of nuclear architecture in the DNA damage response'.

Research Publications

Hinde E, Kong X, Yokomori K, Gratton E. Chromatin dynamics during DNA repair revealed by pair correlation analysis of molecular flow. Biophysical Journal 2014; 107(1): 55-65.

Research Group

Hinde laboratory: Biophysics of Nuclear Organisation



Faculty Research Themes

Cancer

School Research Themes

Cancer in Biomedicine, Cellular Imaging & Structural Biology, Molecular Mechanisms of Disease



Key Contact

For further information about this research, please contact the research group leader.

Department / Centre

Biochemistry and Molecular Biology

Unit / Centre

Hinde laboratory: Biophysics of Nuclear Organisation


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