title: The Arabidopsis thaliana homolog of the helicase RTEL1 plays multiple roles in preserving genome stability.
abstract: In humans, mutations in the DNA helicase Regulator of Telomere Elongation Helicase1 (RTEL1) lead to Hoyeraal-Hreidarsson syndrome, a severe, multisystem disorder. Here, we demonstrate that the RTEL1 homolog in Arabidopsis thaliana plays multiple roles in preserving genome stability. RTEL1 suppresses homologous recombination in a pathway parallel to that of the DNA translocase FANCM. Cytological analyses of root meristems indicate that RTEL1 is involved in processing DNA replication intermediates independently from FANCM and the nuclease MUS81. Moreover, RTEL1 is involved in interstrand and intrastrand DNA cross-link repair independently from FANCM and (in intrastrand cross-link repair) parallel to MUS81. RTEL1 contributes to telomere homeostasis; the concurrent loss of RTEL1 and the telomerase TERT leads to rapid, severe telomere shortening, which occurs much more rapidly than it does in the single-mutant line tert, resulting in developmental arrest after four generations. The double mutant rtel1-1 recq4A-4 exhibits massive growth defects, indicating that this RecQ family helicase, which is also involved in the suppression of homologous recombination and the repair of DNA lesions, can partially replace RTEL1 in the processing of DNA intermediates. The requirement for RTEL1 in multiple pathways to preserve genome stability in plants can be explained by its putative role in the destabilization of DNA loop structures, such as D-loops and T-loops.
authors.affiliation: Botanical Institute II, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Recker
authors.affiliation: Botanical Institute II, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Knoll
authors.affiliation: Botanical Institute II, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany holger.puchta@kit.edu.
authors.forename: Holger
authors.initials: H
authors.lastname: Puchta
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004260:DNA Repair; D042822:Genomic Instability; D059765:Homologous Recombination; D010802:Phylogeny; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D055153:Stem Cell Niche / Q000235:genetics; D059505:Telomere Homeostasis / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D004265:DNA Helicases; C000602077:RTEL1 protein, Arabidopsis