Activation of the transcription factor Oct-1 in response to DNA damage.
Mammalian cells exhibit complex cellular responses to genotoxic stress, including cell cycle checkpoint, DNA repair, and apoptosis. Inactivation of these important biological events will result in genomic instability and cell transformation. It has been demonstrated that gene activation is a critical initial step during the cellular response to DNA damage. A number of investigations have shown that transcription factors are involved in the regulation of stress-inducible genes. These transcription factors include p53, c-Myc, and AP-1 (c-fos and c-jun). However, the role for the octamer-binding transcription factor Oct-1 in the DNA damage-activated response is unknown. In this report, we have presented the novel observation that the transcription factor Oct-1 is induced after cells are exposed to multiple DNA-damaging agents and therapeutic agents, including UV radiation, methylmethane sulfonate, ionizing radiation, etoposide, cisplatin, and camptothecin. The induction of the Oct-1 protein is mediated through a posttranscriptional mechanism and does not require the normal cellular function of the tumor suppressor p53, indicating that the Oct-1 protein, as a transcription factor, may play a role in p53-independent gene activation. In addition to increased protein level, the activity of Oct-1 DNA binding to its specific consensus sequence is also enhanced by DNA damage. Therefore, these results have implicated that the transcription factor Oct-1 might participate in cellular response to DNA damage, particularly in p53-independent gene activation.
Zhao
H
H
Department of Radiation Oncology, Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pennsylvania 15213, USA.
Jin
S
S
Fan
F
F
Fan
W
W
Tong
T
T
Zhan
Q
Q
D004249:DNA Damage / Q000502:physiology*; D004273:DNA, Neoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004586:Electrophoresis; D006367:HeLa Cells; D051863:Host Cell Factor C1; D006801:Humans; D008741:Methyl Methanesulfonate; D009153:Mutagens; D050811:Octamer Transcription Factor-1; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D051863:Host Cell Factor C1; D009153:Mutagens; D050811:Octamer Transcription Factor-1; C494165:POU2F1 protein, human; D012333:RNA, Messenger; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D008741:Methyl Methanesulfonate