The histone chaperones <scp>ASF1</scp> and <scp>HIRA</scp> are required for telomere length and <scp>45S rDNA</scp> copy number homeostasis
Genome stability is significantly influenced by the precise coordination of chromatin complexes that facilitate the loading and eviction of histones from chromatin during replication, transcription, and DNA repair processes. In this study, we investigate the role of the Arabidopsis H3 histone chaperones ANTI-SILENCING FUNCTION 1 (ASF1) and HISTONE REGULATOR A (HIRA) in the maintenance of telomeres and 45S rDNA loci, genomic sites that are particularly susceptible to changes in the chromatin structure. We find that both ASF1 and HIRA are essential for telomere length regulation, as telomeres are significantly shorter in asf1a1b and hira mutants. However, these shorter telomeres remain localized around the nucleolus and exhibit a comparable relative H3 occupancy to the wild type. In addition to regulating telomere length, ASF1 and HIRA contribute to silencing 45S rRNA genes and affect their copy number. Besides, ASF1 supports global heterochromatin maintenance. Our findings also indicate that ASF1 transiently binds to the TELOMERE REPEAT BINDING 1 protein and the N terminus of telomerase in vivo, suggesting a physical link between the ASF1 histone chaperone and the telomere maintenance machinery.
Authors
- Samuel Le Goff (ORCID: https://orcid.org/0000-0002-9991-6435)
- Jasmin Bassler
- Michal Franek (ORCID: https://orcid.org/0000-0002-9627-1301)
- Jana Schwarzerová (ORCID: https://orcid.org/0000-0003-2918-9313)
- Aline V. Probst (ORCID: https://orcid.org/0000-0001-9534-8058)
- Céline Duc (ORCID: https://orcid.org/0000-0001-7426-4541)
- Adéla Machelová
- Martin Demko (ORCID: https://orcid.org/0009-0000-3679-738X)
- Martina Dvořáčková (ORCID: https://orcid.org/0000-0001-5998-6159)
- G Mougeot (ORCID: https://orcid.org/0000-0003-3576-7300)
- Lauriane Simon (ORCID: https://orcid.org/0000-0001-7285-9437)
- Sophie Desset (ORCID: https://orcid.org/0000-0002-4897-4977)
- Martina Nešpor Dadejová
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of Vienna (AT)
- Gregor Mendel Institute of Molecular Plant Biology (AT)
- Austrian Academy of Sciences (AT)
- Inserm (FR)
- Université Clermont Auvergne (FR)
- Masaryk University (CZ)
- Central European Institute of Technology – Masaryk University (CZ)
- Vienna Biocenter (AT)
- Institut Génétique, Reproduction et Développement (FR)
- Unité en Sciences Biologiques et Biotechnologies de Nantes (FR)
- Brno University of Technology (CZ)
- Nantes Université (FR)
Publication Details
- Journal
- The Plant Journal
- Published
- 2024-10-14
- DOI
- https://doi.org/10.1111/tpj.17041
- Citations
- 2
- Primary Topic
- Chromosomal and Genetic Variations
- Type
- article
- Field-Weighted Citation Impact
- 1.20
Funders
- Agence Nationale de la Recherche
- Grantová Agentura České Republiky
- Masarykova Univerzita
- European Regional Development Fund
- Erasmus+