Small RNA-mediated repair of UV-induced DNA lesions by the DNA DAMAGE-BINDING PROTEIN 2 and ARGONAUTE 1.
As photosynthetic organisms, plants need to prevent irreversible UV-induced DNA lesions. Through an unbiased, genome-wide approach, we have uncovered a previously unrecognized interplay between Global Genome Repair and small interfering RNAs (siRNAs) in the recognition of DNA photoproducts, prevalently in intergenic regions. Genetic and biochemical approaches indicate that, upon UV irradiation, the DNA DAMAGE-BINDING PROTEIN 2 (DDB2) and ARGONAUTE 1 (AGO1) ofArabidopsis thalianaform a chromatin-bound complex together with 21-nt siRNAs, which likely facilitates recognition of DNA damages in an RNA/DNA complementary strand-specific manner. The biogenesis of photoproduct-associated siRNAs involves the noncanonical, concerted action of RNA POLYMERASE IV, RNA-DEPENDENT RNA POLYMERASE-2, and DICER-LIKE-4. Furthermore, the chromatin association/dissociation of the DDB2-AGO1 complex is under the control of siRNA abundance and DNA damage signaling. These findings reveal unexpected nuclear functions for DCL4 and AGO1, and shed light on the interplay between small RNAs and DNA repair recognition factors at damaged sites.
Institut de Biologie Moléculaire des Plantes, CNRS, F-67084 Strasbourg, France.
Catherine
C
Schalk
Institut de Biologie Moléculaire des Plantes, CNRS, F-67084 Strasbourg, France.
Valérie
V
Cognat
Institut de Biologie Moléculaire des Plantes, CNRS, F-67084 Strasbourg, France.
Stéfanie
S
Graindorge
Institut de Biologie Moléculaire des Plantes, CNRS, F-67084 Strasbourg, France.
Timothée
T
Vincent
RNA Biology, Department of Biology, Swiss Federal Institute of Technology - Zürich (ETH-Z), Zürich, 8092 Zürich, Switzerland.
Olivier
O
Voinnet
Institut de Biologie Moléculaire des Plantes, CNRS, F-67084 Strasbourg, France; Jean.Molinier@ibmp-cnrs.unistra.fr.
Jean
J
Molinier
D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004260:DNA Repair / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D030821:Plants, Genetically Modified; D011740:Pyrimidine Dimers / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D002843:Chromatin; C530204:DDB2 protein, Arabidopsis; D004268:DNA-Binding Proteins; D011740:Pyrimidine Dimers; D018749:RNA, Plant; D034741:RNA, Small Interfering; C504982:DCL4 protein, Arabidopsis; D043244:Ribonuclease III
Arabidopsis; DNA photolesions; DNA repair; small RNA