title: DNA damage triggers SAF-A and RNA biogenesis factors exclusion from chromatin coupled to R-loops removal.
abstract: We previously identified the heterogeneous ribonucleoprotein SAF-A/hnRNP U as a substrate for DNA-PK, a protein kinase involved in DNA damage response (DDR). Using laser micro-irradiation in human cells, we report here that SAF-A exhibits a two-phase dynamics at sites of DNA damage, with a rapid and transient recruitment followed by a prolonged exclusion. SAF-A recruitment corresponds to its binding to Poly(ADP-ribose) while its exclusion is dependent on the activity of ATM, ATR and DNA-PK and reflects the dissociation from chromatin of SAF-A associated with ongoing transcription. Having established that SAF-A RNA-binding domain recapitulates SAF-A dynamics, we show that this domain is part of a complex comprising several mRNA biogenesis proteins of which at least two, FUS/TLS and TAFII68/TAF15, exhibit similar biphasic dynamics at sites of damage. Using an original reporter for live imaging of DNA:RNA hybrids (R-loops), we show a transient transcription-dependent accumulation of R-loops at sites of DNA damage that is prolonged upon inhibition of RNA biogenesis factors exclusion. We propose that a new component of the DDR is an active anti-R-loop mechanism operating at damaged transcribed sites which includes the exclusion of mRNA biogenesis factors such as SAF-A, FUS and TAF15.
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France Equipe Labellisée Ligue Nationale Contre le Cancer.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Britton
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France Equipe Labellisée Ligue Nationale Contre le Cancer.
authors.forename: Emma
authors.initials: E
authors.lastname: Dernoncourt
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France Equipe Labellisée Ligue Nationale Contre le Cancer.
authors.forename: Christine
authors.initials: C
authors.lastname: Delteil
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France.
authors.forename: Carine
authors.initials: C
authors.lastname: Froment
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France.
authors.forename: Odile
authors.initials: O
authors.lastname: Schiltz
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Salles
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France Equipe Labellisée Ligue Nationale Contre le Cancer philippe.frit@ipbs.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Frit
authors.affiliation: CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), BP 64182, 205 route de Narbonne, F-31077 Toulouse, Cedex 4, France Université de Toulouse, UPS, IPBS, F-31077 Toulouse, France Equipe Labellisée Ligue Nationale Contre le Cancer patrick.calsou@ipbs.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Calsou
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004249:DNA Damage; D034722:Heterogeneous-Nuclear Ribonucleoprotein U / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D017434:Protein Structure, Tertiary; D034702:RNA-Binding Protein FUS / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D034722:Heterogeneous-Nuclear Ribonucleoprotein U; D034702:RNA-Binding Protein FUS; D016601:RNA-Binding Proteins; C102041:TAF15 protein, human; D035381:TATA-Binding Protein Associated Factors; D011064:Poly Adenosine Diphosphate Ribose; D019869:Phosphatidylinositol 3-Kinases