The makings of TERRA R-loops at chromosome ends
| Autor: | Rita Valador Fernandes, Marianna Feretzaki, Joachim Lingner |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Telomerase
Transcription Genetic r-loops DNA repair RAD51 homologous recombination Review length mammalian telomeres Biology Shelterin Complex break-induced replication Homology directed repair repeat-containing rna Neoplasms Animals Humans Molecular Biology Telomere Shortening Repetitive Sequences Nucleic Acid par-terra distinct Cell Cycle terra DNA replication Recombinational DNA Repair Telomere Homeostasis DNA rad51 Cell Biology telomeres Shelterin recombination Cell biology Telomere shelterin proteins chromatin RNA Long Noncoding Rad51 Recombinase telomere elongation R-Loop Structures transcription Homologous recombination Signal Transduction Developmental Biology |
| Zdroj: | Cell Cycle article-version (VoR) Version of Record |
| ISSN: | 1551-4005 1538-4101 |
| Popis: | Telomeres protect chromosome ends from nucleolytic degradation, uncontrolled recombination by DNA repair enzymes and checkpoint signaling, and they provide mechanisms for their maintenance by semiconservative DNA replication, telomerase and homologous recombination. The telomeric long noncoding RNA TERRA is transcribed from a large number of chromosome ends. TERRA has been implicated in modulating telomeric chromatin structure and checkpoint signaling, and in telomere maintenance by homology directed repair, and telomerase – when telomeres are damaged or very short. Recent work indicates that TERRA association with telomeres involves the formation of DNA:RNA hybrid structures that can be formed post transcription by the RAD51 DNA recombinase, which in turn may trigger homologous recombination between telomeric repeats and telomere elongation. In this review, we describe the mechanisms of TERRA recruitment to telomeres, R-loop formation and its regulation by shelterin proteins. We discuss the consequences of R-loop formation, with regard to telomere maintenance by DNA recombination and how this may impinge on telomere replication while counteracting telomere shortening in normal cells and in ALT cancer cells, which maintain telomeres in the absence of telomerase. |
| Databáze: | OpenAIRE |
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