MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context

Iben Bach Bentsen; Ida Nielsen; Michael Lisby; Helena Berner Nedergaard Nielsen; Souvik Sen Gupta; Kamilla Mundbjerg; Anni Hangaard Andersen; Lotte Bjergbæk

doi:10.1093/nar/gkt051

MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context

Iben Bach Bentsen, Ida Nielsen, Michael Lisby, Helena Berner Nedergaard Nielsen, Souvik Sen Gupta, Kamilla Mundbjerg, Anni Hangaard Andersen, Lotte Bjergbæk

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

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Abstract

To address how eukaryotic replication forks respond to fork stalling caused by strong non-covalent protein–DNA barriers, we engineered the controllable Fob-block system in Saccharomyces cerevisiae. This system allows us to strongly induce and control replication fork barriers (RFB) at their natural location within the rDNA. We discover a pivotal role for the MRX (Mre11, Rad50, Xrs2) complex for fork integrity at RFBs, which differs from its acknowledged function in double-strand break processing. Consequently, in the absence of the MRX complex, single-stranded DNA (ssDNA) accumulates at the rDNA. Based on this, we propose a model where the MRX complex specifically protects stalled forks at protein–DNA barriers, and its absence leads to processing resulting in ssDNA. To our surprise, this ssDNA does not trigger a checkpoint response. Intriguingly, however, placing RFBs ectopically on chromosome VI provokes a strong Rad53 checkpoint activation in the absence of Mre11. We demonstrate that proper checkpoint signalling within the rDNA is restored on deletion of SIR2. This suggests the surprising and novel co

Original language	English
Journal	Nucleic Acids Research
Volume	41
Issue	5
Pages (from-to)	3173-3189
Number of pages	17
ISSN	0305-1048
DOIs	https://doi.org/10.1093/nar/gkt051
Publication status	Published - 1 Feb 2013

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title = "MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context",

abstract = "To address how eukaryotic replication forks respond to fork stalling caused by strong non-covalent protein–DNA barriers, we engineered the controllable Fob-block system in Saccharomyces cerevisiae. This system allows us to strongly induce and control replication fork barriers (RFB) at their natural location within the rDNA. We discover a pivotal role for the MRX (Mre11, Rad50, Xrs2) complex for fork integrity at RFBs, which differs from its acknowledged function in double-strand break processing. Consequently, in the absence of the MRX complex, single-stranded DNA (ssDNA) accumulates at the rDNA. Based on this, we propose a model where the MRX complex specifically protects stalled forks at protein–DNA barriers, and its absence leads to processing resulting in ssDNA. To our surprise, this ssDNA does not trigger a checkpoint response. Intriguingly, however, placing RFBs ectopically on chromosome VI provokes a strong Rad53 checkpoint activation in the absence of Mre11. We demonstrate that proper checkpoint signalling within the rDNA is restored on deletion of SIR2. This suggests the surprising and novel co",

author = "Bentsen, {Iben Bach} and Ida Nielsen and Michael Lisby and Nielsen, {Helena Berner Nedergaard} and {Sen Gupta}, Souvik and Kamilla Mundbjerg and Andersen, {Anni Hangaard} and Lotte Bjergb{\ae}k",

year = "2013",

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doi = "10.1093/nar/gkt051",

language = "English",

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pages = "3173--3189",

journal = "Nucleic Acids Research",

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MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context. / Bentsen, Iben Bach; Nielsen, Ida; Lisby, Michael et al.
In: Nucleic Acids Research, Vol. 41, No. 5, 01.02.2013, p. 3173-3189.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

TY - JOUR

T1 - MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context

AU - Bentsen, Iben Bach

AU - Nielsen, Ida

AU - Lisby, Michael

AU - Nielsen, Helena Berner Nedergaard

AU - Sen Gupta, Souvik

AU - Mundbjerg, Kamilla

AU - Andersen, Anni Hangaard

AU - Bjergbæk, Lotte

PY - 2013/2/1

Y1 - 2013/2/1

N2 - To address how eukaryotic replication forks respond to fork stalling caused by strong non-covalent protein–DNA barriers, we engineered the controllable Fob-block system in Saccharomyces cerevisiae. This system allows us to strongly induce and control replication fork barriers (RFB) at their natural location within the rDNA. We discover a pivotal role for the MRX (Mre11, Rad50, Xrs2) complex for fork integrity at RFBs, which differs from its acknowledged function in double-strand break processing. Consequently, in the absence of the MRX complex, single-stranded DNA (ssDNA) accumulates at the rDNA. Based on this, we propose a model where the MRX complex specifically protects stalled forks at protein–DNA barriers, and its absence leads to processing resulting in ssDNA. To our surprise, this ssDNA does not trigger a checkpoint response. Intriguingly, however, placing RFBs ectopically on chromosome VI provokes a strong Rad53 checkpoint activation in the absence of Mre11. We demonstrate that proper checkpoint signalling within the rDNA is restored on deletion of SIR2. This suggests the surprising and novel co

AB - To address how eukaryotic replication forks respond to fork stalling caused by strong non-covalent protein–DNA barriers, we engineered the controllable Fob-block system in Saccharomyces cerevisiae. This system allows us to strongly induce and control replication fork barriers (RFB) at their natural location within the rDNA. We discover a pivotal role for the MRX (Mre11, Rad50, Xrs2) complex for fork integrity at RFBs, which differs from its acknowledged function in double-strand break processing. Consequently, in the absence of the MRX complex, single-stranded DNA (ssDNA) accumulates at the rDNA. Based on this, we propose a model where the MRX complex specifically protects stalled forks at protein–DNA barriers, and its absence leads to processing resulting in ssDNA. To our surprise, this ssDNA does not trigger a checkpoint response. Intriguingly, however, placing RFBs ectopically on chromosome VI provokes a strong Rad53 checkpoint activation in the absence of Mre11. We demonstrate that proper checkpoint signalling within the rDNA is restored on deletion of SIR2. This suggests the surprising and novel co

U2 - 10.1093/nar/gkt051

DO - 10.1093/nar/gkt051

M3 - Journal article

C2 - 23376930

SN - 0305-1048

VL - 41

SP - 3173

EP - 3189

JO - Nucleic Acids Research

JF - Nucleic Acids Research

IS - 5

ER -

MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context

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