Show simple item record

dc.contributor.author
Duda, Heike
dc.contributor.supervisor
Werner, Sabine
dc.contributor.supervisor
Matos, Joao
dc.contributor.supervisor
Barral, Yves
dc.date.accessioned
2018-08-31T09:17:51Z
dc.date.available
2017-08-30T10:21:48Z
dc.date.available
2017-08-30T11:40:54Z
dc.date.available
2018-08-31T09:14:20Z
dc.date.available
2018-08-31T09:17:51Z
dc.date.issued
2017
dc.identifier.uri
http://hdl.handle.net/20.500.11850/181777
dc.identifier.doi
10.3929/ethz-b-000181777
dc.description.abstract
DNA replication and chromosome segregation are essential processes in the cell cycle, but in eukaryotes are incompatible with each other, as they require vastly different cellular environments. In interphase, branched DNA structures are generated in high numbers as intermediates of DNA replication and/or repair. In mitosis, the same intermediates give rise to genome instability: they physically interfere with the segregation of the partly replicated chromosomes. To minimize the risk to genome integrity, eukaryotic cells separate DNA replication and chromosome segregation in time. Furthermore, if replication intermediates persist, they are targeted for nucleolytic resolution at the onset of mitosis, by the structure-selective endonuclease MUS81. How MUS81 function is regulated to prevent deleterious processing of intact replication intermediates in S-phase was unclear. In this work, I investigated the regulation of MUS81 function on replication intermediates in human cell lines. I found that while MUS81 is catalytically active throughout the cell cycle, efficient substrate targeting requires association with the nuclease scaffold SLX4. MUS81-SLX4 association is cell cycle regulated and requires CDK1-mediated phosphorylation of SLX4. To prevent unscheduled processing of replication intermediates during S-phase, WEE1 kinase phosphorylates and inhibits CDK1. Accordingly, inhibition of WEE1 led to premature MUS81-SLX4 association and localization of MUS81 to S-phase chromatin. At the same time, WEE1 inhibition halted DNA replication and led to catastrophic MUS81-dependent chromosome pulverization. Hence, I propose that by inhibiting CDK1 activity in S-phase, WEE1 indirectly prevents premature association of MUS81 and SLX4 and safeguards DNA replication by preventing untimely processing of replication intermediates. Surprisingly, MUS81-SLX4 was required not only for chromosome fragmentation in WEE1 inhibited cells, but also for premature mitotic entry caused by untimely CDK1 activity in S-phase. Restoring DNA replication by depletion of MUS81-SLX4 delayed CDK1 activation and mitotic entry upon WEE1 inhibition until after bulk DNA replication was concluded. I propose that active replication leads to the generation of a signal that delays mitotic entry, thus assisting WEE1 in ensuring appropriate S-phase length. Delaying mitotic entry indirectly delays MUS81-SLX4 assembly. Conversely, MUS81-SLX4 association during mitosis promotes targeted resolution of persistent replication intermediates and safeguards chromosome segregation. The resulting double-negative feedback loop between replication intermediates and a replication fork processing nuclease, MUS81-SXL4, will contribute to rendering DNA replication and mitosis mutually exclusive in eukaryotes.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
ETH Zurich
en_US
dc.rights.uri
http://rightsstatements.org/page/InC-NC/1.0/
dc.subject
CDK1
en_US
dc.subject
DNA replication
en_US
dc.subject
EME2
en_US
dc.subject
MUS81
en_US
dc.subject
PLK1
en_US
dc.subject
SLX4
en_US
dc.subject
WEE1
en_US
dc.subject
cell cycle
en_US
dc.subject
chromosome pulverization
en_US
dc.title
Cell cycle regulation of DNA breakage by MUS81 nuclease
en_US
dc.type
Doctoral Thesis
dc.rights.license
In Copyright - Non-Commercial Use Permitted
dc.date.published
2017-08-30
ethz.size
103 p.
en_US
ethz.code.ddc
DDC - DDC::5 - Science::570 - Life sciences
en_US
ethz.grant
Coordination of DNA repair and segregation during meiosis and mitosis
en_US
ethz.grant
Rewiring the DNA repair machinery for genome stability and haploidisation
en_US
ethz.identifier.diss
24367
en_US
ethz.publication.place
Zurich
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02030 - Dep. Biologie / Dep. of Biology
en_US
ethz.grant.agreementno
153058
ethz.grant.agreementno
155823
ethz.grant.fundername
SNF
ethz.grant.fundername
SNF
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.program
Projektförderung in Biologie und Medizin (Abteilung III)
ethz.grant.program
ethz.date.deposited
2017-08-30T10:21:52Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.date.embargoend
2018-08-30
ethz.rosetta.installDate
2017-08-30T11:42:56Z
ethz.rosetta.lastUpdated
2020-02-15T14:41:11Z
ethz.rosetta.versionExported
true
ethz.COinS
ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Cell%20cycle%20regulation%20of%20DNA%20breakage%20by%20MUS81%20nuclease&rft.date=2017&rft.au=Duda,%20Heike&rft.genre=unknown&rft.btitle=Cell%20cycle%20regulation%20of%20DNA%20breakage%20by%20MUS81%20nuclease
 Search via SFX

Files in this item

Thumbnail

Publication type

Show simple item record