title: Histone H1 chaperone activity of TAF-I is regulated by its subtype-dependent intramolecular interaction.
abstract: Linker histone H1 is involved in the regulation of gene activity through the maintenance of higher-order chromatin structure. Previously, we have shown that template activating factor-I (TAF-I or protein SET) is involved in linker histone H1 dynamics as a histone H1 chaperone. In human and murine cells, two TAF-I subtypes exist, namely TAF-Iα and TAF-Iβ. TAF-I has a highly acidic amino acid cluster in its C-terminal region and forms homo- or heterodimers through its dimerization domain. Both dimer formation and the C-terminal region of TAF-I are essential for the histone chaperone activity. TAF-Iα exhibits less histone chaperone activity compared with TAF-Iβ even though TAF-Iα and β differ only in their N-terminal regions. However, it is unclear how subtype-specific TAF-I activities are regulated. Here, we have shown that the N-terminal region of TAF-Iα autoinhibits its histone chaperone activity via intramolecular interaction with its C-terminal region. When the interaction between the N- and C-terminal regions of TAF-Iα is disrupted, TAF-Iα shows a histone chaperone activity similar to that of TAF-Iβ. Taken together, these results provide mechanistic insights into the concept that fine tuning of TAF-I histone H1 chaperone activity relies on the subtype compositions of the TAF-I dimer.
authors.affiliation: Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.|University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Kajitani
authors.affiliation: Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.|University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Kato
authors.affiliation: University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Nagata
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D006657:Histones / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009928:Organ Specificity; D011485:Protein Binding; D012617:Sea Urchins; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006657:Histones; D014157:Transcription Factors