title: Comparative aspects of polyglutamine binding domain in PQBP-1 among Vertebrata.
abstract: We investigated the evolutionary conservation of polyglutamine binding protein-1 (PQBP-1) among Vertebrata. PQBP-1s were highly conserved and shared the same domain features including a WW domain, a polar amino acid rich domain (PRD), a nuclear localization signal (NLS), and a C-terminal domain (CTD) among Eutheria, but not always among Vertebrata. PQBP-1s of Vertebrata contained a variable region in the middle portion corresponding to the position of PRD. The full form of PRD including both 7aa and DR/ER repeats was specific to Eutheria. PRD of non-eutherian Amniota was minimal. Amphibia had no PRD. The DR/ER repeat was solo in fishes. Agnatha PRD was also rich in polar amino acids, but contained no repetitive sequence. We investigated 3 polyQ-containing proteins known to interact with PQBP-1: BRN-2, Huntingtin, and ATAXIN-1, and showed a diverse nature of protein-protein interaction in Vertebrata. There appears to be no interaction between PQBP-1 and BRN-2, Huntingtin, or ATAXIN-1 in Amphibia, while the interaction between PQBP-1 and BRN-2 is expected to be conserved among Mammalia, and the interaction between PQBP-1 and Huntingtin or ATAXIN-1 depends on the lineage in Eutheria.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan. mnas@cdb.riken.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Nasu
authors.forename: Fuzuki
authors.initials: F
authors.lastname: Mizuno
authors.forename: Shintaroh
authors.initials: S
authors.lastname: Ueda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014714:Vertebrates
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C119246:PQBP1 protein, human; D010455:Peptides; C097188:polyglutamine