title: Effect of DNA on filament formation of tau microtubule-binding domain: structural dependence of DNA.
abstract: To examine whether or not DNA accelerates the paired helical filament (PHF) formation of tau, the effect of various types of DNAs on filament formations of three-repeated and four-repeated microtubule-binding domains (3RMBD and 4RMBD, respectively) of tau protein was investigated by monitoring the change of thioflavin S fluorescence intensity, that is parallel to the filament formation. Consequently, the followings were clarified: 1) the structurally rigid double-stranded DNA such as poly(dG-dC) or calf thymus DNA has the high potency of promoting the filament formations of 3RMBD and 4RMBD, 2) the filament formation of 3RMBD was more promoted than that of 4RMBD, due to the intermolecular dimer formation of 3RMBD, 3) the DNA-promoted filament formations of these MBDs were temperature-dependent, and the single-stranded DNA such as poly(dA) or poly(dT) reversely protected 4RMBD from the molecular assembly at 20 degrees C. These are the first report on the function of DNA for the PHF formation of tau protein.
authors.affiliation: Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Hikosou
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Kurabayashi
authors.forename: Michiko
authors.initials: M
authors.lastname: Doumoto
authors.forename: Kaoru
authors.initials: K
authors.lastname: Hoshitoku
authors.forename: Fumie
authors.initials: F
authors.lastname: Mizushima
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Minoura
authors.forename: Koji
authors.initials: K
authors.lastname: Tomoo
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Ishida
mesh_terms: D000595:Amino Acid Sequence; D003599:Cytoskeleton / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure; D004247:DNA / Q000737:chemistry* / Q000494:pharmacology; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000494:pharmacology; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017434:Protein Structure, Tertiary / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013696:Temperature; D016875:tau Proteins / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D004277:DNA, Single-Stranded; D016875:tau Proteins; D004247:DNA