The histone chaperones ASF1 and HIRA are required for telomere length and 45S rDNA copy number homeostasis
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Date
2024-10-14
Authors
Machelová, Adéla
Dadejová, Martina
Franek, Michal
Mougeot, Guillaume
Simon, Lauriane
Le Goff, Samuel
Duc, Celine
Bassler, Jasmin
Demko, Martin
Schwarzerová, Jana
ORCID
0000-0003-2918-9313Advisor
Referee
Mark
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
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Abstract
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.
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Citation
PLANT JOURNAL. 2024, vol. 120, issue 3, p. 1125-1141.
https://onlinelibrary.wiley.com/doi/abs/10.1111/tpj.17041
https://onlinelibrary.wiley.com/doi/abs/10.1111/tpj.17041
Document type
Peer-reviewed
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Published version
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Language of document
en