title: Comparative genetics of the poly-Q tract of ataxin-1 and its binding protein PQBP-1.
abstract: Human PQBP-1 is known to interact with triplet repeat disease gene products such as ataxin and huntingtin through their poly-glutamine (poly-Q) tracts. The poly-Q tracts show extensive variation in both the number and the configuration of repeats among species. A surface plasmon resonance assay showed clear interaction between human PQBP-1 and Q(11), representative of the poly-Q tract of the ataxin-1 of Old World monkeys. No response was observed using Q(2)PQ(2)P(4)Q(2), representative of the poly-Q tract of the ataxin-1 of New World monkeys. This implies that the interaction of human PQBP-1 with ataxin-1 is limited to humans and closely related species. Comparison of the human and mouse PQBP-1 sequences showed an elevated amino acid substitution rate in the polar amino acid-rich domain of PQBP-1 that is responsible for binding to poly-Q tracts. This could have been advantageous to the new biological function of human PQBP-1 through poly-Q tracts.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Japan.
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Kurosaki
authors.forename: Jun
authors.initials: J
authors.lastname: Gojobori
authors.forename: Shintaroh
authors.initials: S
authors.lastname: Ueda
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000067696:Ataxin-1; D000067528:Ataxins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D004268:DNA-Binding Proteins; D019143:Evolution, Molecular; D014644:Genetic Variation; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics*; D011323:Primates / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: C000593749:ATXN1 protein, human; D000067696:Ataxin-1; D000067528:Ataxins; C000593750:Atxn1 protein, mouse; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C119246:PQBP1 protein, human