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.