title: Identification and characterization of a nuclear localization signal of TRIM28 that overlaps with the HP1 box.
abstract: Tripartite motif-containing 28 (TRIM28) is a transcription regulator, which forms a repressor complex containing heterochromatin protein 1 (HP1). Here, we report identification of a nuclear localization signal (NLS) within the 462-494 amino acid region of TRIM28 that overlaps with its HP1 binding site, HP1 box. GST-pulldown experiments revealed the interaction of the arginine-rich TRIM28 NLS with various importin α subtypes (α1, α2 and α4). In vitro transport assay demonstrated that nuclear localization of GFP-TRIM28 NLS is mediated by importin αs, in conjunction with importin β1 and Ran. Further, we demonstrated that HP1 and importin αs compete for binding to TRIM28. Together, our findings suggest that importin α has an essential role in the nuclear delivery and preferential HP1 interaction of TRIM28.
authors.affiliation: Laboratory of Nuclear Transport Dynamics, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Moriyama
authors.affiliation: Laboratory of Nuclear Transport Dynamics, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan.
authors.forename: Percival
authors.initials: P
authors.lastname: Sangel
authors.affiliation: School of Medicine, Osaka University, Osaka 565-0871, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Chikashi
authors.initials: C
authors.lastname: Obuse
authors.affiliation: Laboratory of Nuclear Transport Dynamics, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Laboratory of Nuclear Transport Dynamics, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan; Laboratory of Biomedical Innovation, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan. Electronic address: moka@nibiohn.go.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Oka
authors.affiliation: National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka 567-0085, Japan; Laboratory of Biomedical Innovation, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka 565-0871, Japan. Electronic address: y-yoneda@nibiohn.go.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yoneda
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D001665:Binding Sites; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000076183:Tripartite Motif-Containing Protein 28; D028901:alpha Karyopherins / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D028961:beta Karyopherins / Q000737:chemistry / Q000145:classification / Q000378:metabolism
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D028901:alpha Karyopherins; D028961:beta Karyopherins; D000090266:Chromobox Protein Homolog 5; C101116:TRIM28 protein, human; D000076183:Tripartite Motif-Containing Protein 28
keywords: HP1; Importin α; KAP1; NLS; TIF1β; TRIM28