UV-C response of the ribonucleotide reductase large subunit involves both E2F-mediated gene transcriptional regulation and protein subcellular relocalization in tobacco cells.
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.
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France.
Frédéric
F
Lincker
Gabriel
G
Philipps
Marie-Edith
ME
Chabouté
D021581:Active Transport, Cell Nucleus; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000502:physiology*; D050684:E2F Transcription Factors; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020218:Response Elements; D012264:Ribonucleotide Reductases / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D016196:S Phase; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation; D014466:Ultraviolet Rays
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D021122:Protein Subunits; D014157:Transcription Factors; D012264:Ribonucleotide Reductases