title: Activation of the ATR kinase by the RPA-binding protein ETAA1.
abstract: Activation of the ATR kinase following perturbations to DNA replication relies on a complex mechanism involving ATR recruitment to RPA-coated single-stranded DNA via its binding partner ATRIP and stimulation of ATR kinase activity by TopBP1. Here, we discovered an independent ATR activation pathway in vertebrates, mediated by the uncharacterized protein ETAA1 (Ewing's tumour-associated antigen 1). Human ETAA1 accumulates at DNA damage sites via dual RPA-binding motifs and promotes replication fork progression and integrity, ATR signalling and cell survival after genotoxic insults. Mechanistically, this requires a conserved domain in ETAA1 that potently and directly stimulates ATR kinase activity independently of TopBP1. Simultaneous loss of ETAA1 and TopBP1 gives rise to synthetic lethality characterized by massive genome instability and abrogation of ATR-dependent signalling. Our findings demonstrate that parallel TopBP1- and ETAA1-mediated pathways underlie ATR activation and that their combined action is essential for coping with replication stress.
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Haahr
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Saskia
authors.initials: S
authors.lastname: Hoffmann
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Maxim A X
authors.initials: MA
authors.lastname: Tollenaere
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.|Center for Chromosome Stability, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Teresa
authors.initials: T
authors.lastname: Ho
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Luis Ignacio
authors.initials: LI
authors.lastname: Toledo
authors.affiliation: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Mann
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Simon
authors.initials: S
authors.lastname: Bekker-Jensen
authors.affiliation: Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Markus
authors.identifier: http://orcid.org/0000-0002-6737-7203
authors.initials: M
authors.lastname: Räschle
authors.affiliation: The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.|Center for Chromosome Stability, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
authors.forename: Niels
authors.identifier: http://orcid.org/0000-0002-6623-709X
authors.initials: N
authors.lastname: Mailand
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation
chemical_list: C521194:ATRIP protein, human; D048868:Adaptor Proteins, Signal Transducing; D000954:Antigens, Surface; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C508506:ETAA1 protein, human; D009687:Nuclear Proteins; C110513:TOPBP1 protein, human; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins