CtIP tetramer assembly is required for DNA-end resection and repair
Authors
Davies, Owen R
Sun, Meidai
Belotserkovskaya, Rimma
Coates, Julia
Demir, Mukerrem
Morton, Christopher
Rzechorzek, Neil
Publication Date
2015-01-05Journal Title
Nature Structural & Molecular Biology
ISSN
1545-9993
Publisher
Nature Publishing Group
Pages
150-157
Language
English
Type
Article
Metadata
Show full item recordCitation
Davies, O. R., Forment, J., Sun, M., Belotserkovskaya, R., Coates, J., Galanty, Y., Demir, M., et al. (2015). CtIP tetramer assembly is required for DNA-end resection and repair. Nature Structural & Molecular Biology, 150-157. https://doi.org/10.1038/nsmb.2937
Abstract
Mammalian CtIP protein has major roles in DNA double-strand break (DSB) repair. Although it is well established that CtIP
promotes DNA-end resection in preparation for homology-dependent DSB repair, the molecular basis for this function has
remained unknown. Here we show by biophysical and X-ray crystallographic analyses that the N-terminal domain of human CtIP
exists as a stable homotetramer. Tetramerization results from interlocking interactions between the N-terminal extensions of
CtIP’s coiled-coil region, which lead to a ‘dimer-of-dimers’ architecture. Through interrogation of the CtIP structure, we identify
a point mutation that abolishes tetramerization of the N-terminal domain while preserving dimerization in vitro. Notably,
we establish that this mutation abrogates CtIP oligomer assembly in cells, thus leading to strong defects in DNA-end resection
and gene conversion. These findings indicate that the CtIP tetramer architecture described here is essential for effective
DSB repair by homologous recombination.
Sponsorship
We thank M. Kilkenny for help with the collection of X-ray diffraction data,
A. Sharff and P. Keller for help with X-ray data processing and J.D. Maman for
assistance with SEC-MALS. This work was supported by a Wellcome Trust Senior
Research Fellowship award in basic biomedical sciences (L.P.), an Isaac Newton
Trust research grant (L.P. and O.R.D.) and a Cambridge Overseas Trust PhD
studentship (M.D.S.). Research in the laboratory of S.P.J. is funded by Cancer
Research UK (CRUK; programme grant C6/A11224), the European Research
Council and the European Community Seventh Framework Programme
(grant agreement no. HEALTH-F2-2010-259893 (DDResponse)). Core funding
is provided by Cancer Research UK (C6946/A14492) and the Wellcome
Trust (WT092096). S.P.J. receives his salary from the University of Cambridge,
supplemented by CRUK. J.V.F. is funded by Cancer Research UK programme
grant C6/A11224 and the Ataxia Telangiectasia Society. R.B. and J.C. are funded by
Cancer Research UK programme grant C6/A11224. Y.G. and M.D. are funded by
the European Research Council grant DDREAM.
Funder references
Cancer Research UK (11224)
WELLCOME TRUST (104641/Z/14/Z)
European Research Council (268536)
Wellcome Trust (084279/Z/07/A)
Wellcome Trust (092096/Z/10/Z)
Cancer Research UK (A14492)
Identifiers
External DOI: https://doi.org/10.1038/nsmb.2937
This record's URL: https://www.repository.cam.ac.uk/handle/1810/246946
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