title: Thermodynamic characterization of the interaction between the human Y-box binding protein YB-1 and nucleic acids.
abstract: Y-box binding protein 1 (YB-1) binds to both RNA and DNA to control transcription and translation for the regulation of various cellular systems. YB-1 is overexpressed in some cancer cells and is a potential target for treatment of cancer. Herein, we describe isothermal titration calorimetry analyses of the interaction between a number of recombinant YB-1 domains and nucleic acids to identify the RNA and DNA binding sites and their binding mechanisms. These results demonstrated that the C-terminal domain of the protein interacts with single-stranded DNA and RNA by exothermic and endothermic reactions, respectively. The highly conserved cold-shock domain (CSD) also bound to single-stranded RNA and DNA by exothermic and endothermic reactions, respectively. The specific binding manner for RNA is in the CSD, whereas DNA binds with the most affinity to the C-terminal region (amino acids 130-219). We found further that the C-terminal region (amino acids 220-324) regulates the binding stoichiometry of RNA. These quantitative thermodynamic results provide a preliminary indication on the molecular mechanism of binding of the multifunctional protein YB-1 to nucleic acids to regulate its biological function.
authors.affiliation: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Satoru
authors.initials: S
authors.lastname: Nagatoishi
authors.forename: Kouhei
authors.initials: K
authors.lastname: Tsumoto
mesh_terms: D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D009154:Mutation; D009696:Nucleic Acids / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D012313:RNA / Q000378:metabolism; D013696:Temperature; D013816:Thermodynamics; D051840:Y-Box-Binding Protein 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D009696:Nucleic Acids; D051840:Y-Box-Binding Protein 1; D012313:RNA