title: Molecular mechanisms of transcriptional regulation by the nuclear zinc-finger protein Zfat in T cells.
abstract: Zfat is a nuclear protein with AT-hook and zinc-finger domains. We previously reported that Zfat plays crucial roles in T-cell survival and development in mice. However, the molecular mechanisms whereby Zfat regulates gene expression in T cells remain unexplored. In this study, we analyzed the genome-wide occupancy of Zfat by chromatin immunoprecipitation with sequencing (ChIP-seq), which showed that Zfat bound predominantly to a region around a transcription start site (TSS), and that an 8-bp nucleotide sequence GAA(T/A)(C/G)TGC was identified as a consensus sequence for Zfat-binding sites. Furthermore, about half of the Zfat-binding sites were characterized by histone H3 acetylations at lysine 9 and lysine 27 (H3K9ac/K27ac). Notably, Zfat gene deletion decreased the H3K9ac/K27ac levels at the Zfat-binding sites, suggesting that Zfat may be related to the regulation of H3K9ac/K27ac. Integrated analysis of ChIP-seq and transcriptional profiling in thymocytes identified Zfat-target genes with transcription to be regulated directly by Zfat. We then focused on the chromatin regulator Brpf1, a Zfat-target gene, revealing that Zfat bound directly to a 9-bp nucleotide sequence, CGAANGTGC, which is conserved among mammalian Brpf1 promoters. Furthermore, retrovirus-mediated re-expression of Zfat in Zfat-deficient peripheral T cells restored Brpf1 expression to normal levels, and shRNA-mediated Brpf1 knockdown in peripheral T cells increased the proportion of apoptotic cells, suggesting that Zfat-regulated Brpf1 expression was important for T-cell survival. Our findings demonstrated that Zfat regulates the transcription of target genes by binding directly to the TSS proximal region, and that Zfat-target genes play important roles in T-cell homeostasis.
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Shuhei
authors: S
authors: Ishikura
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Toshiyuki
authors: T
authors: Tsunoda
authors: Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.
authors: Kazuhiko
authors: K
authors: Nakabayashi
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Keiko
authors: K
authors: Doi
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Midori
authors: M
authors: Koyanagi
authors: Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.
authors: Keiko
authors: K
authors: Hayashi
authors: Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.
authors: Tomoko
authors: T
authors: Kawai
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Yoko
authors: Y
authors: Tanaka
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Yuri
authors: Y
authors: Iwaihara
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Hao
authors: H
authors: Luo
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
authors: Kensuke
authors: K
authors: Nishi
authors: Department of Laboratory Animal Medicine, Research Institute, National Center for Global Health and Medicine, Tokyo 162-8655, Japan; Section of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo 162-8655, Japan.
authors: Tadashi
authors: T
authors: Okamura
authors: Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Center for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan. Electronic address: sshirasa@fukuoka-u.ac.jp.
authors: Senji
authors: S
authors: Shirasawa
mesh_terms: D000818:Animals; D047369:Chromatin Immunoprecipitation; D005786:Gene Expression Regulation; D051379:Mice; D060168:Thymocytes / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D014157:Transcription Factors; C529571:ZFAT protein, mouse
keywords: Autoimmune diseases; Brpf1; Histone acetylation; T-cell homeostasis; Transcriptional regulation; Zfat