Chromosomal Single-Strand Break Repair: Mechanisms and Degenerative Disease
Lead Research Organisation:
University of Sussex
Department Name: Sch of Life Sciences
Abstract
Breaks in the genetic material (DNA) can lead to a variety of hereditary and age-related diseases, including cancer and neurodegeneration. Whilst the causal link between DNA breaks and cancer is quite well understood, the causal link between DNA breaks and degeneration of the nervous system is not. The aim of the proposed programme is to address critical unanswered questions and new hypotheses concerning the mechanism/s by which breaks in a single strand of DNA (DNA single-strand breaks) are repaired, and the link between this process and degenerative disease. Understanding how DNA single-strand breaks can cause neurodegeneration is important not only for understanding hereditary diseases associated with neurological dysfunction (and hopefully in future for treating and managing such diseases), but most likely also for understanding degenerative diseases associated with normal ageing. This is because DNA single-strand breaks are the commonest lesions arising in cells and are a product of oxidative stress, which in turn is a major etiological factor in pathologies associated with ageing. Indeed, our recent experiments reveal that loss of the critical DNA single-strand break repair protein XRCC1 results in premature onset of molecular and pathological hallmarks of ageing and, moreover, that un-repaired DNA damage in the brain can trigger these hallmarks, systemically (i.e. in undamaged tissues). In addition, we have identified molecular links between the DNA damage response and the hereditary neurodegenerative disease ataxia oculomotor apraxia-2, which we propose identifies a new component of the cellular control of gene expression in the presence of DNA lesions and can explain the basis of this disease. We will now pursue our recent novel findings and hypotheses in this research Programme. In particular, we will address critical questions concerning the organisation and importance of DNA single-strand break repair in vivo, focussing on a novel unidentified role for XRCC1 and on the mechanism by which this protein is recruited at single-strand breaks, and on how DNA single-strand break repair impacts on hereditary and ageing-related degenerative disease. Ultimately, we envisage this work will identify new avenues for treatment & management of degenerative diseases that are associated, wholly or partly, with DNA breakage.
Technical Summary
The aim of the proposed programme is to address critical unanswered questions and new hypotheses concerning mechanism/s of DNA single-strand break repair and the link between this process and human degenerative disease. For example, we will employ molecular and cellular approaches to pursue the new molecular links we have uncovered between the response to DNA strand breaks and the hereditary neurodegenerative disease, ataxia oculomotor apraxia-2. This work will involve the use of siRNA and gene targeting technology in human, DT40, and murine cells, in conjunction with biochemical assays that measure DNA strand break repair and related processes in vitro. The proposed programme is relevant not only to hereditary neurodegenerative disease, however, but also to degenerative pathologies associated with normal human ageing. This is because we have found that loss of the critical DNA single-strand break repair scaffold protein XRCC1 in brain results in premature onset of molecular/pathological hallmarks of ageing, systemically. We will thus also pursue these findings in the new Programme, using not only the cellular model systems described above but also physiological approaches. Finally, we will address key unanswered questions concerning the organisation and importance of DNA single-strand break repair in vivo, focussing on a critical but unidentified role for XRCC1, and on how XRCC1 function is modulated within the context of chromatin by the proteins APLF and PARP-1. To do this, we will again employ a combination of biochemical, cellular, and physiological approaches. Together, the experiments proposed in this research Programme will enable us to address both critical unanswered questions concerning cellular mechanisms of DNA single-strand break repair and also the pathophysiological consequences of not repairing such breaks.
Planned Impact
Beyond academia and related research fields, the work in this Programme has the potential to impact, in the long-term, on the health sector and 'quality of life'/'Lifelong Health and Wellbeing'. This is because the Programme will address the possible impact of DNA single-strand breaks on the maintenance of normal neurological function and on molecular hallmarks/pathologies associated with normal ageing. For example, the programme will investigate the link between un-repaired DNA strand breaks and progressive, debilitating, degeneration of the nervous system in the hereditary genetic disease, ataxia oculomotor apraxia-2. In addition, the programme will investigate the link between un-repaired single-strand breaks in the brain and consequent down-regulation of growth hormone signalling in the liver; a molecular hallmark of normal ageing that can influence pathologies such as osteoporosis. A thorough understanding of the relationship between un-repaired SSBs and pathologies associated with hereditary neurodegenerative disease and with age could thus help inform the health sector in respect to etiological factors that promote degenerative disease and 'unhealthy' ageing (e.g. environmental factors that induce excessive SSBs). This research could thus, in the long-term, inform on environmental and life-style issues relating to 'quality of life' and 'Lifelong Health and Wellbeing'.
Organisations
- University of Sussex (Lead Research Organisation)
- St Jude Children's Hospital (Collaboration)
- University of Zurich (Project Partner)
- Washington State University (Project Partner)
- University of Pittsburgh (Project Partner)
- St. Jude Children's Research Hospital (Project Partner)
- Research Triangle Institute (Project Partner)
People |
ORCID iD |
Keith Caldecott (Principal Investigator) |
Publications
Polo LM
(2019)
Efficient Single-Strand Break Repair Requires Binding to Both Poly(ADP-Ribose) and DNA by the Central BRCT Domain of XRCC1.
in Cell reports
Caldecott KW
(2014)
Protein ADP-ribosylation and the cellular response to DNA strand breaks.
in DNA repair
Rulten SL
(2013)
DNA strand break repair and neurodegeneration.
in DNA repair
Caldecott KW
(2014)
DNA single-strand break repair.
in Experimental cell research
Nardozza AP
(2016)
Nick Your DNA, Mark Your Chromatin.
in Molecular cell
Hoch NC
(2017)
XRCC1 mutation is associated with PARP1 hyperactivation and cerebellar ataxia.
in Nature
Grundy GJ
(2016)
PARP3 is a sensor of nicked nucleosomes and monoribosylates histone H2B(Glu2).
in Nature communications
Gómez-Herreros F
(2014)
TDP2 protects transcription from abortive topoisomerase activity and is required for normal neural function.
in Nature genetics
Breslin C
(2015)
The XRCC1 phosphate-binding pocket binds poly (ADP-ribose) and is required for XRCC1 function.
in Nucleic acids research
Description | Input into MRC research straegy |
Geographic Reach | National |
Policy Influence Type | Participation in a guidance/advisory committee |
Description | Cellular and Pathological Responses to Chromosome DNA Single-Strand Breaks |
Amount | £1,940,871 (GBP) |
Funding ID | MR/P010121/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 05/2017 |
End | 04/2022 |
Description | ERC Advanced Investigator Award |
Amount | € 2,447,409 (EUR) |
Funding ID | SIDSCA RC-2015-AdG-69499615 |
Organisation | European Research Council (ERC) |
Sector | Public |
Country | Belgium |
Start | 10/2016 |
End | 09/2021 |
Description | MRC Project Grant 2012 (MR/K01854X/1) |
Amount | £360,000 (GBP) |
Funding ID | MR/K01854X/1 |
Organisation | Medical Research Council (MRC) |
Sector | Public |
Country | United Kingdom |
Start | 05/2013 |
End | 04/2016 |
Description | McKinnon and Mouse Models |
Organisation | St Jude Children's Hospital |
Country | United States |
Sector | Hospitals |
PI Contribution | My group provided expertise in the cellular analysis of single-strand break repair, and manpower (including a sabbatical period for one of my students) |
Collaborator Contribution | This collaboration enabled my group to introduce expertise in mouse model systmes into our work. This was necessary to progress our research into the link between single-strand break repair and neurodegenerative diseases. |
Impact | This collaboration was crucial in the development of my laboratory - allowing me to introduce mouse model systems into my programme of work. This was a critical aspect of the work currently being conducted under the auspices of my current MRC programme grant (G0600776). The sabbatical period for my student (Sherif F El Khamisy) also provided the experience necessary for him to deveop his own research laboratory, with subsequent funding from the Wellcome Trust. Several publications have emerged from this collaboration - one of which was financially supported by this grant (17914460)and two (19303373 & 19633665) that were supported by my current MRC programme grant (G0600776). |
Start Year | 2006 |
Description | MRC Centenary Exhibition |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | Yes |
Type Of Presentation | Workshop Facilitator |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | local school teachers/colleges and students/pupils visited a day of presentations on our research and its importance for health,culminating in several keynote talks that sparked discussion and conversation this has encouraged further interest in our work experience week |
Year(s) Of Engagement Activity | 2013 |
Description | Work experience 2010-2013 |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | Yes |
Type Of Presentation | Workshop Facilitator |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | Each year I host and organise a work experience week in for four-six children/yr from several local schools. During the week, the children participate in a variety of different scientific experiments in several different laboratories, with the intention of illustrating what a career in science is like. schools typically receive great feedback from the students, who seem to enjoy the experience. This year, one school has also asked me to contribute to a career "speed dating" event in Jan 2013 |
Year(s) Of Engagement Activity | 2010,2011,2012 |