title: Proteome analysis of a rat liver nuclear insoluble protein fraction and localization of a novel protein, ISP36, to compartments in the interchromatin space.
abstract: A rat liver nuclear insoluble protein fraction was analyzed to investigate candidate proteins participating in nuclear architecture formation. Proteins were subjected to two-dimensional separation by reversed-phase HPLC in 60% formic acid and SDS/PAGE. The method produced good resolution of insoluble proteins. One hundred and thirty-eight proteins were separated, and 28 of these were identified. The identified proteins included one novel protein, seven known nuclear proteins and 12 known nuclear matrix proteins. The novel 36 kDa protein was further investigated for its subnuclear localization. The human ortholog of the protein was expressed in Escherichia coli and antibodies were raised against the recombinant protein. Exclusive localization of the protein to the nuclear insoluble protein fraction was confirmed by cell fractionation followed by immunoblotting. Immunostaining of mouse C3H cells suggested that the 36 kDa protein was a constituent of an insoluble macromolecular complex spread throughout the interchromatin space of the nucleus. The protein was designated 'interchromatin space protein of 36 kDa', ISP36.
authors.affiliation: Natural Science Course, Graduate School of Science and Technology, Niigata University, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Segawa
authors.forename: Koko
authors.initials: K
authors.lastname: Niino
authors.forename: Reiko
authors.initials: R
authors.lastname: Mineki
authors.forename: Naoko
authors.initials: N
authors.lastname: Kaga
authors.forename: Kimie
authors.initials: K
authors.lastname: Murayama
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Furukawa
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Horigome
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D020543:Proteome; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012995:Solubility
chemical_list: D002843:Chromatin; D018076:DNA, Complementary; D009687:Nuclear Proteins; D020543:Proteome; D011994:Recombinant Proteins