クリバヤシ フトシ   Futoshi Kuribayashi
  栗林 太
   所属   川崎医科大学  医学部 基礎医学 生化学
   職種   教授
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 EBF1 acts as a powerful repressor of Blimp-1 gene expression in immature B cells.
掲載誌名 正式名:Biochem Biophys Res Commun.
略  称:BBRC
巻・号・頁 422(4),780-785頁
著者・共著者 Hidehiko Kikuchi, Masami Nakayama, Yasunari Takami, Futoshi Kuribayashi, Tatsuo Nakayama
発行年月 2012/06
概要 The transcription factor, early B cell factor 1 (EBF1) with an atypical zinc-finger and helix-loop-helix motif, is essential for development and differentiation of lymphocytes. In mice, EBF1 is involved in the generation of pre-pro B cells (the first specified progenitors of B cells) from common lymphoid progenitors (CLPs) and transcription regulations of various genes involved in B cell-development, for instance, mb-1 and Pax5. During B lymphopoiesis, interestingly, EBF1 is detected throughout from CLPs to mature B cells. However, in immature B cells, the physiological role of EBF1 remains to be elucidated. Here, by analyzing EBF1-deficient DT40 cells, EBF1(-/-), generated by us, we show that EBF1-deficiency caused significant increases (to ∼800%) in both mRNA and protein levels of B lymphocyte-induced maturation protein-1 (Blimp-1), the master gene for plasma cell differentiation. In addition, both transcription and protein synthesis of Blimp-1 were remarkably down-regulated (to ∼20%) by re-expression (over-expression) of EBF1. Chromatin immunoprecipitation assay revealed that EBF1 binds to proximal 5'-upstream regions around two putative EBF1 binding motifs of the gene in vivo. These results suggest that EBF1 takes part in transcriptional regulations of the Blimp-1 gene in immature B cells, and may play a key role in B cell differentiation. This is the first report on a novel EBF1 function in immature B cells as a powerful repressor of Blimp-1 gene expression.