title: Role of Template Activating Factor-I as a chaperone in linker histone dynamics.
abstract: Linker histone H1 is a fundamental chromosomal protein involved in the maintenance of higher-ordered chromatin organization. The exchange dynamics of histone H1 correlates well with chromatin plasticity. A variety of core histone chaperones involved in core histone dynamics has been identified, but the identity of the linker histone chaperone in the somatic cell nucleus has been a long-standing unanswered question. Here we show that Template Activating Factor-I (TAF-I, also known as protein SET) is involved in histone H1 dynamics as a linker histone chaperone. Among previously identified core histone chaperones and linker histone chaperone candidates, only TAF-I was found to be associated specifically with histone H1 in mammalian somatic cell nuclei. TAF-I showed linker histone chaperone activity in vitro. Fluorescence recovery after photobleaching analyses revealed that TAF-I is involved in the regulation of histone H1 dynamics in the nucleus. Therefore, we propose that TAF-I is a key molecule that regulates linker histone-mediated chromatin assembly and disassembly.
authors.affiliation: Department of Infection Biology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Kato
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Okuwaki
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Nagata
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D004268:DNA-Binding Proteins; D036681:Fluorescence Recovery After Photobleaching; D006367:HeLa Cells; D056488:Histone Chaperones / Q000737:chemistry / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D007700:Kinetics; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D011506:Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D012359:tRNA Methyltransferases
chemical_list: D004268:DNA-Binding Proteins; C569262:H1-1 protein, human; D056488:Histone Chaperones; D006657:Histones; C104356:NAP1L4 protein, human; D009687:Nuclear Proteins; D009707:Nucleosomes; D010446:Peptide Fragments; D011506:Proteins; D011994:Recombinant Proteins; C513473:SET protein, human; D014157:Transcription Factors; C498548:TRMO protein, human; D012359:tRNA Methyltransferases