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.
Lincker
Frédéric
F
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France.
Philipps
Gabriel
G
Chabouté
Marie-Edith
ME
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