Rdp1, a novel zinc finger protein, regulates the DNA damage response of rhp51(+) from Schizosaccharomyces pombe.
The Schizosaccharomyces pombe DNA repair gene rhp51(+) encodes a RecA-like protein with the DNA-dependent ATPase activity required for homologous recombination. The level of the rhp51(+) transcript is increased by a variety of DNA-damaging agents. Its promoter has two cis-acting DNA damage-responsive elements (DREs) responsible for DNA damage inducibility. Here we report identification of Rdp1, which regulates rhp51(+) expression through the DRE of rhp51(+). The protein contains a zinc finger and a polyalanine tract similar to ones previously implicated in DNA binding and transactivation or repression, respectively. In vitro footprinting and competitive binding assays indicate that the core consensus sequences (NGG/TTG/A) of DRE are crucial for the binding of Rdp1. Mutations of both DRE1 and DRE2 affected the damage-induced expression of rhp51(+), indicating that both DREs are required for transcriptional activation. In addition, mutations in the DREs significantly reduced survival rates after exposure to DNA-damaging agents, demonstrating that the damage response of rhp51(+) enhances the cellular repair capacity. Surprisingly, haploid cells containing a complete rdp1 deletion could not be recovered, indicating that rdp1(+) is essential for cell viability and implying the existence of other target genes. Furthermore, the DNA damage-dependent expression of rhp51(+) was significantly reduced in checkpoint mutants, raising the possibility that Rdp1 may mediate damage checkpoint-dependent transcription of rhp51(+).
Shim
Y S
YS
School of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
Jang
Y K
YK
Lim
M S
MS
Lee
J S
JS
Seong
R H
RH
Hong
S H
SH
Park
S D
SD
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004352:Drug Resistance, Microbial; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D008741:Methyl Methanesulfonate / Q000633:toxicity; D008969:Molecular Sequence Data; D011485:Protein Binding; D051135:Rad51 Recombinase; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014466:Ultraviolet Rays / Q000009:adverse effects; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C084232:RHP51 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D008741:Methyl Methanesulfonate; D051135:Rad51 Recombinase; D000251:Adenosine Triphosphatases; C416926:Rdp1 protein, S pombe