title: RPA and Rad51 constitute a cell intrinsic mechanism to protect the cytosol from self DNA.
abstract: Immune recognition of cytosolic DNA represents a central antiviral defence mechanism. Within the host, short single-stranded DNA (ssDNA) continuously arises during the repair of DNA damage induced by endogenous and environmental genotoxic stress. Here we show that short ssDNA traverses the nuclear membrane, but is drawn into the nucleus by binding to the DNA replication and repair factors RPA and Rad51. Knockdown of RPA and Rad51 enhances cytosolic leakage of ssDNA resulting in cGAS-dependent type I IFN activation. Mutations in the exonuclease TREX1 cause type I IFN-dependent autoinflammation and autoimmunity. We demonstrate that TREX1 is anchored within the outer nuclear membrane to ensure immediate degradation of ssDNA leaking into the cytosol. In TREX1-deficient fibroblasts, accumulating ssDNA causes exhaustion of RPA and Rad51 resulting in replication stress and activation of p53 and type I IFN. Thus, the ssDNA-binding capacity of RPA and Rad51 constitutes a cell intrinsic mechanism to protect the cytosol from self DNA.
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Wolf
authors.affiliation: Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
authors.forename: Alexander
authors.identifier: 0000-0001-9108-3929
authors.initials: A
authors.lastname: Rapp
authors.affiliation: Department of Dermatology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Berndt
authors.affiliation: Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Staroske
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Schuster
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Dobrick-Mattheuer
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Kretschmer
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Nadja
authors.initials: N
authors.lastname: König
authors.affiliation: Biotechnology Center, Technische Universität Dresden, 01307 Dresden, Germany.|Center for Regenerative Therapies, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kurth
authors.affiliation: Institute of Human Genetics, Heinrich-Heine-University, Medical Faculty, 40225 Düsseldorf, Germany.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Wieczorek
authors.affiliation: Department of Gynecology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Kast
authors.affiliation: Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Cardoso
authors.affiliation: Department of Dermatology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Günther
authors.affiliation: Department of Pediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany.
authors.forename: Min Ae
authors.initials: MA
authors.lastname: Lee-Kirsch
mesh_terms: D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007370:Interferon Type I / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D034622:RNA Interference; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*; D051716:Replication Protein A / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D004277:DNA, Single-Stranded; D007370:Interferon Type I; D010750:Phosphoproteins; D051716:Replication Protein A; D016159:Tumor Suppressor Protein p53; D051135:Rad51 Recombinase; D005090:Exodeoxyribonucleases; C429526:three prime repair exonuclease 1