title: Novel TDP2-ubiquitin interactions and their importance for the repair of topoisomerase II-mediated DNA damage.
abstract: Tyrosyl DNA phosphodiesterase 2 (TDP2) is a multifunctional protein implicated in DNA repair, signal transduction and transcriptional regulation. In its DNA repair role, TDP2 safeguards genome integrity by hydrolyzing 5'-tyrosyl DNA adducts formed by abortive topoisomerase II (Top2) cleavage complexes to allow error-free repair of DNA double-strand breaks, thereby conferring cellular resistance against Top2 poisons. TDP2 consists of a C-terminal catalytic domain responsible for its phosphodiesterase activity, and a functionally uncharacterized N-terminal region. Here, we demonstrate that this N-terminal region contains a ubiquitin (Ub)-associated (UBA) domain capable of binding multiple forms of Ub with distinct modes of interactions and preference for either K48- or K63-linked polyUbs over monoUb. The structure of TDP2 UBA bound to monoUb shows a canonical mode of UBA-Ub interaction. However, the absence of the highly conserved MGF motif and the presence of a fourth α-helix make TDP2 UBA distinct from other known UBAs. Mutations in the TDP2 UBA-Ub binding interface do not affect nuclear import of TDP2, but severely compromise its ability to repair Top2-mediated DNA damage, thus establishing the importance of the TDP2 UBA-Ub interaction in DNA repair. The differential binding to multiple Ub forms could be important for responding to DNA damage signals under different contexts or to support the multi-functionality of TDP2.
authors.affiliation: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Timsi
authors.initials: T
authors.lastname: Rao
authors.affiliation: Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Saeko
authors.initials: S
authors.lastname: Takada
authors.affiliation: Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Muthana
authors.initials: M
authors.lastname: Al Abo
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Chen
authors.affiliation: Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA.
authors.forename: Kylie J
authors.initials: KJ
authors.lastname: Walters
authors.affiliation: Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Yves
authors.initials: Y
authors.lastname: Pommier
authors.affiliation: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA aihar001@umn.edu.
authors.forename: Hideki
authors.initials: H
authors.lastname: Aihara
mesh_terms: D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D004249:DNA Damage / Q000502:physiology; D004260:DNA Repair / Q000502:physiology*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004330:Drosophila / Q000235:genetics; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000378:metabolism; D000072417:Protein Domains; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D025801:Ubiquitin; D010727:Phosphoric Diester Hydrolases; C474866:TDP2 protein, human; C000620180:tdpt-1 protein, C elegans; D004250:DNA Topoisomerases, Type II