Lincker Frédéric, Philipps Gabriel, Chabouté Marie-Edith
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France.
Nucleic Acids Res. 2004 Feb 27;32(4):1430-8. doi: 10.1093/nar/gkh310. Print 2004.
E2F factors are implicated in various cellular processes including specific gene induction at the G1/S transition of the cell cycle. We present in this study a novel regulatory aspect for the tobacco large subunit of ribonucleotide reductase (R1a) and its encoding gene (RNR1a) in the UV-C response. By structural analyses, two E2F sites were identified on the promoter of this gene. Functional analysis showed that, in addition to their role in the specific G1/S induction of the RNR1a gene, both E2F sites were important for regulating specific RNR1a gene expression in response to UV-C irradiation in non-synchronized and synchronized cells. Concomitantly, western blot and cellular analyses showed an increase of a 60 kDa E2F factor and a transient translocation of a GFP-R1a protein fusion from cytoplasm to nucleus in response to UV irradiation.
E2F因子参与多种细胞过程，包括在细胞周期的G1/S转换时诱导特定基因。在本研究中，我们展示了核糖核苷酸还原酶（R1a）的烟草大亚基及其编码基因（RNR1a）在UV-C应答中的一种新的调控方式。通过结构分析，在该基因的启动子上鉴定出两个E2F位点。功能分析表明，除了在RNR1a基因的特定G1/S诱导中发挥作用外，这两个E2F位点对于在非同步化和同步化细胞中响应UV-C照射调节特定的RNR1a基因表达也很重要。同时，蛋白质印迹和细胞分析表明，响应UV照射，一种60 kDa的E2F因子增加，并且GFP-R1a蛋白融合体从细胞质向细胞核发生瞬时转位。
