2019-03-14
Focusing on the Versatile Transcription-Coupled DNA Repair Pathway
Publication
Publication
Een focus op het veelzijdige transcriptie-gekoppelde DNA reparatieproces
Many aspects of TC-NER have been described since the discovery of this
versatile DNA damage repair pathway three decades ago [123]. However,
many crucial questions regarding its exact molecular mechanism and the
manner in which it deals with different types of lesions remain
unanswered [31].
To further unravel the TC-NER mechanism, sensitive techniques that can
specifically measure TC-NER activity would be of great value. In Chapter 2
the development of a new, single-cell assay that can quantify TC-NER
activity is described. This immunofluorescence-based method allows the
direct measurement of TC-NER activity in an user-friendly manner.
Furthermore, this sensitive assay not only enables the measurements of
TC-NER and GG-NER activity on low, physiological relevant, UV-C doses (2
J/m2), but also allows detection and quantification of the activity of other
excision repair pathways.
Thus far, the exact mechanism how UVSSA is recruited to the TC-NER
complex remains elusive. Therefore, we studied the accumulation of
UVSSA on UV-C induced DNA damage in Chapter 3. Using live cell
microscopy, we showed that UVSSA is recruited to DNA damage in a CSA
and CSB independent manner. We further showed, using specific UVSSA
deletion mutants that the DUF2043 domain is important for its
recruitment to UV-induced DNA damage. To identify factors involved in
the recruitment of UVSSA to DNA damage, a quantitative mass
spectrometry approach was used to reveal proteins that specifically
interact with the DUF2043 domain. With this approach we identified the
FACT subunit Spt16 as a novel UVSSA interactor and follow-up studies
indicated that Spt16 is involved in the recruitment of UVSSA to sites of
DNA damage.
As UVSSA is hypothesised to be involved in the response to both UV and
oxidative induced DNA damage, in Chapter 4 we used quantitative
interaction proteomics to identify UVSSA interactions that were
specifically induced following UV-C or H2O2 induced DNA damage. In this
chapter we describe the damage-specific UVSSA interaction partners,
discuss their potential roles and propose that UVSSA might have different
functions following UV or oxidative DNA damage.
In Chapter 5, the function of the TC-NER factor CSB during the repair of
oxidative damage was analysed. Live cell imaging studies indicated that
the recruitment of XRCC1 to oxidative lesions is dependent on functional
CSB and active transcription, whereas recruitment of the BER-initiating
glycosylase OGG1 does not require transcription or CSB. Based on our data
we propose a model in which CSB facilitates XRCC1 recruitment to RNA
polymerase II complexes stalled at BER-intermediates. These results
further establish the importance of CSB in BER.
In Chapter 6 we discuss the main findings of the experimental work
described in this thesis and provide future directions to study the role and
molecular function of TC-NER factors in the repair of different types of
DNA damage.
Additional Metadata | |
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W. Vermeulen (Wim) , J.A. Marteijn (Jurgen) | |
Erasmus University Rotterdam | |
hdl.handle.net/1765/115408 | |
Organisation | Department of Molecular Genetics |
Wienholz, F. (2019, March 14). Focusing on the Versatile Transcription-Coupled DNA Repair Pathway. Retrieved from http://hdl.handle.net/1765/115408 |