H2AH2B_Propagation · Elucidating the propagation and function of H2A and H2B modifications across DNA replication
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-09-01 → 2022-12-05
- EU contribution
- €207,312
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Elucidating the propagation and function of H2A and H2B modifications across DNA replication
Genetic information is packaged into the cell nucleus by histones proteins, which, together with their modifications, regulate gene expression and thus control which cell type is formed and maintained over time (epigenetic memory). However, whenever the cell divides, it duplicates its genetic information during DNA replication, which also requires double the amount of histone proteins and their modifications to faithfully propagate epigenetic memory. If the appropriate copying of these modificiations fails, the memory of what genes have to be expressed can get lost, which is a recurrent problem in aging and diseases such as cancer. Only few studies so far have investigated how the propagation of epigenetic memory mechanistically works during DNA replication, and they have only looked at histone proteins H3 and H4, while histone proteins H2A and H2B have not been studied in their role in that process. In this project, I sought to uncover the exact mechanisms and properties of how H2A and H2B proteins and their modifications are handled during DNA replication. I could demonstrate that epigenetic information on H2A and H2B is also propagated during DNA replication in a way that is independent of H3-H4 and that it is important to accurately restore epigenetic information on histones H3 and H4. This newly identified mechanism explains how cells remember their cell type also during DNA replication and will help us in the future to understand the issues arising in aging and cancer, where epigenetic cell memory is lost.
Data: CORDIS, © European Union
Project objective
Chromatin and its accompanying histone marks are fundamental for correct, cell type-specific gene expression and thus important to ensure cellular identity of each cell. Importantly, this requires that the chromatin landscape is accurately propagated and maintained across DNA replication, a process which is still not well understood. While there have been insights into how histone H3 and H4 marks are transmitted to daughter cells, information on H2A and H2B marks are still missing. Using mouse embryonic stem cells, I will gain first insights into how modifications on H2A and H2B are maintained during DNA replication, and their impact on restoring the parental chromatin landscape on replicated DNA, with the following three specific objectives:(1) I will investigate the propagation principles and kinetics of H2A/H2B modifications during DNA replication using a combination of advanced mass spectrometry and genomic approaches with a focus on ubiquitinated H2A/H2B.(2) I will gain mechanistic insights into the importance of H2A/H2B ubiquitination on chromatin reestablishment with a degron-based depletion approach targeting H2A/H2B ubiquitin ligases. This will allow me to study if, where and how the H2Aub and H2Bub-dependent histone marks are reestablished and hence reveal important features of histone mark crosstalk during DNA replication.(3) I will determine whether H2A-H2B dimers are propagated symmetrically to the two daughter strands by employing a strand-specific sequencing approach, and test mutants wherein symmetric H3-H4 propagation is compromised.This proposal will provide pioneering insights into how histones H2A and H2B are propagated and unveil the epigenetic inheritance of their marks, and also bring seminal understanding of histone mark crosstalk during DNA replication and across cell division. This will open new research avenues in chromatin research and give me an unique opportunity to follow up on these mechanisms as future, independent researcher.
Original text from CORDIS.
Participants
- KOBENHAVNS UNIVERSITET · KOBENHAVNCoordinatorDenmark
Links
Data: CORDIS, © European Union