Maintenance of genome integrity by histone (de)ubiquitinating enzymes


Wijzig gegevens

Titel Maintenance of genome integrity by histone (de)ubiquitinating enzymes
Looptijd 11 / 2008 - 05 / 2013
Status Lopend
Onderzoeknummer OND1331637
Leverancier gegevens NWO

Samenvatting (EN)

Protein ubiquitination is critical for normal and cancer related processes. Histones are the major mono-ubiquitinated proteins in mammalian cells. The characterization of the Polycomb PRC1 complex as ubiquitin ligase (E3) for histone H2A linked this modification to transcriptional silencing. In addition, recent work by us and others revealed the involvement of ubiquitinated H2A in the response to DNA damage. However, little is known about the molecular mechanisms and the enzymes that remove and regulate this modification. By a biochemical approach, we have recently identified USP3 (ubiquitin-specific protease 3), as a deubiquitinating enzyme (DUB) for H2A and H2B. Our results implicate USP3 as a novel chromatin modifier in the maintenance of genome integrity and point to a potential role of USP3 in chromatin rearrangements during DNA replication. Here, I propose to explore the mechanism of USP3-mediated DNA damage response and to identify novel components of the histone ubiquitination machinery. Main aims of this proposal are: (i) The use of RNA interference tools to investigate USP3 function in mammalian cell culture systems. The role of USP3 in DNA damage response/DNA repair will be addressed. (i) Biochemical approaches will be employed to identify USP3 interacting proteins/novel substrates as well as to address its regulation. (iii) I will exploit our recently developed biochemical approach to isolate novel histone-specific E3 ligases and DUBs. For this, I will combine protein chromatography techniques with in vitro ubiquitination assays and MALDI mass spectrometric analysis. I expect that the characterization of USP3 and the identification of novel enzymes implicated in histone (de)ubiquitination will help in understanding the role of this modification in epigenetic mechanisms and its involvement in normal and neoplastic cell growth. Epigenetic alterations are potentially reversible. From a medical point of view, this holds important prospects for drug development and treatment of cancer

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Betrokken personen

Projectleider Dr. E. Citterio

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