title: Possible involvement of a pertussis toxin-sensitive GTP-binding protein in protein transport into nuclei isolated from rat liver.
abstract: Nuclear protein transport was inhibited in permeabilized HeLa cells which had been prepared after culture with pertussis toxin, suggesting that the pertussis toxin-sensitive protein(s) might be involved in the nuclear protein transport. To investigate the mechanism whereby pertussis toxin inhibited the nuclear protein transport, an accumulation of proteins containing a nuclear localization signal sequence (NLS) into isolated rat liver nuclei was investigated. The NLS-containing protein accumulation required ATP and cytosolic proteins, and was temperature- and wheat germ agglutinin-sensitive as had been observed in permeabilized cells. Non-hydrolyzable GTP analogues, such as guanosine 5'-(gamma-thio)triphosphate and guanosine 5'-(beta, gamma-methylene)triphosphate, but not ATP analogues, inhibited the NLS-containing protein accumulation in the isolated nuclei. The NLS-containing protein accumulation was also inhibited by prior treatment of the nuclei with pertussis toxin plus NAD, and the effect of pertussis toxin was blocked when guanosine 5'-(gamma-thio)triphosphate was simultaneously added during the pretreatment with pertussis toxin. The inhibition induced by pertussis toxin and the blockage by guanosine 5'-(gamma-thio)triphosphate were well correlated to ADP-ribosylation of 40-kDa protein in nuclear fraction. These results suggested that the nuclear pertussis toxin-sensitive GTP-binding protein is involved in a pathway of nuclear protein transport.
authors.affiliation: Department of Life Science, Tokyo Institute of Technology, Yokohama.
authors.forename: Y
authors.initials: Y
authors.lastname: Takei
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Kanaho
authors.forename: T
authors.initials: T
authors.lastname: Katada
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000378:metabolism*; D037342:Pertussis Toxin; D051381:Rats; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D006150:Guanine Nucleotides; D009687:Nuclear Proteins; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins