Cryo-H-Rec | Cryo-EM Imaging of Histone Recycling at the Replication Fork

Summary
DNA replication is essential for cell proliferation. In eukaryotic cells, DNA is densely packaged in nucleosome arrays that form chromatin. Such organisation protects the genetic material and controls access to DNA, thus providing an important mechanism for regulating gene expression. The eukaryotic replication machinery has evolved to unravel nucleosomes in order to access and duplicate DNA, while also maintaining chromatin density on newly duplicated DNA. To achieve this, the replisome dismantles nucleosomes ahead of the replication fork and reassembles them on nascent DNA strands, by coordinating redeposition of parental and newly synthesized histones. Histone proteins are subject to an array of post-translational modifications (PTMs), providing an epigenetic code that modulates activation and silencing of specific chromosomal regions. Redeposition of parental histones with their PTMs on both nascent DNA strands is, thus, pivotal in transmission of the epigenetic marks to daughter cells. I intend to perform in vitro reconstitution of the replisome on a chromatinised template and use cryo-electron microscopy to image DNA duplication and parental histone recycling at the replication fork. I seek to describe different structural intermediates in the process of nucleosome disassembly, DNA duplication and histone incorporation into new nucleosomes. To capture and characterise intermediate states of the replication machinery during this concerted process, I will employ a multidisciplinary approach and resort to structural techniques complementary to cryo-EM like solution NMR spectroscopy and crosslinking-mass spectrometry (XL-MS). My results will help dissect the role of different replisome components in nucleosome reshuffling at the replication fork, and elucidate the molecular mechanism that underpins chromosome replication and epigenetic inheritance.
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More information & hyperlinks
Web resources: https://cordis.europa.eu/project/id/845939
Start date: 01-04-2019
End date: 31-03-2021
Total budget - Public funding: 212 933,76 Euro - 212 933,00 Euro
Cordis data

Original description

DNA replication is essential for cell proliferation. In eukaryotic cells, DNA is densely packaged in nucleosome arrays that form chromatin. Such organisation protects the genetic material and controls access to DNA, thus providing an important mechanism for regulating gene expression. The eukaryotic replication machinery has evolved to unravel nucleosomes in order to access and duplicate DNA, while also maintaining chromatin density on newly duplicated DNA. To achieve this, the replisome dismantles nucleosomes ahead of the replication fork and reassembles them on nascent DNA strands, by coordinating redeposition of parental and newly synthesized histones. Histone proteins are subject to an array of post-translational modifications (PTMs), providing an epigenetic code that modulates activation and silencing of specific chromosomal regions. Redeposition of parental histones with their PTMs on both nascent DNA strands is, thus, pivotal in transmission of the epigenetic marks to daughter cells. I intend to perform in vitro reconstitution of the replisome on a chromatinised template and use cryo-electron microscopy to image DNA duplication and parental histone recycling at the replication fork. I seek to describe different structural intermediates in the process of nucleosome disassembly, DNA duplication and histone incorporation into new nucleosomes. To capture and characterise intermediate states of the replication machinery during this concerted process, I will employ a multidisciplinary approach and resort to structural techniques complementary to cryo-EM like solution NMR spectroscopy and crosslinking-mass spectrometry (XL-MS). My results will help dissect the role of different replisome components in nucleosome reshuffling at the replication fork, and elucidate the molecular mechanism that underpins chromosome replication and epigenetic inheritance.

Status

CLOSED

Call topic

MSCA-IF-2018

Update Date

28-04-2024
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Horizon 2020
H2020-EU.1. EXCELLENT SCIENCE
H2020-EU.1.3. EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions (MSCA)
H2020-EU.1.3.2. Nurturing excellence by means of cross-border and cross-sector mobility
H2020-MSCA-IF-2018
MSCA-IF-2018