The Telomeric Protein TRF2 Regulates Replication Origin Activity Within Pericentromeric Heterochromatin
Overview
Authors
Affiliations
Heterochromatic regions render the replication process particularly difficult due to the high level of chromatin compaction and the presence of repeated DNA sequences. In humans, replication through pericentromeric heterochromatin requires the binding of a complex formed by the telomeric factor TRF2 and the helicase RTEL1 in order to relieve topological barriers blocking fork progression. Since TRF2 is known to bind the Origin Replication Complex (ORC), we hypothesized that this factor could also play a role at the replication origins (ORI) of these heterochromatin regions. By performing DNA combing analysis, we found that the ORI density is higher within pericentromeric satellite DNA repeats than within bulk genomic DNA and decreased upon TRF2 downregulation. Moreover, we showed that TRF2 and ORC2 interact in pericentromeric DNA, providing a mechanism by which TRF2 is involved in ORI activity. Altogether, our findings reveal an essential role for TRF2 in pericentromeric heterochromatin replication by regulating both replication initiation and elongation.
Chromatin's Influence on Pre-Replication Complex Assembly and Function.
Ahmad H, Chetlangia N, Prasanth S Biology (Basel). 2024; 13(3).
PMID: 38534422 PMC: 10968542. DOI: 10.3390/biology13030152.
The nucleolar protein GNL3 prevents resection of stalled replication forks.
Lebdy R, Canut M, Patouillard J, Cadoret J, Letessier A, Ammar J EMBO Rep. 2023; 24(12):e57585.
PMID: 37965896 PMC: 10702807. DOI: 10.15252/embr.202357585.
MiR-182-3p targets TRF2 and impairs tumor growth of triple-negative breast cancer.
Dinami R, Pompili L, Petti E, Porru M, DAngelo C, Di Vito S EMBO Mol Med. 2022; 15(1):e16033.
PMID: 36426578 PMC: 9832842. DOI: 10.15252/emmm.202216033.
Selective pericentromeric heterochromatin dismantling caused by TP53 activation during senescence.
Mendez-Bermudez A, Lototska L, Pousse M, Tessier F, Croce O, Latrick C Nucleic Acids Res. 2022; 50(13):7493-7510.
PMID: 35819196 PMC: 9303393. DOI: 10.1093/nar/gkac603.
TRF2-mediated ORC recruitment underlies telomere stability upon DNA replication stress.
Higa M, Matsuda Y, Fujii J, Sugimoto N, Yoshida K, Fujita M Nucleic Acids Res. 2021; 49(21):12234-12251.
PMID: 34761263 PMC: 8643664. DOI: 10.1093/nar/gkab1004.