Induction of a cell stress response gene RTP801 by DNA damaging agent methyl methanesulfonate through CCAAT/enhancer binding protein.
RTP801 is a newly discovered stress response gene that is induced by hypoxia and other cell stress signals. Here, we investigated the mechanism by which a DNA damaging agent, methyl methanesulfonate (MMS), induces RTP801 transcription. In HaCaT human keratinocytes, MMS was able to induce a rapid increase in the mRNA level of RTP801. Correspondingly, MMS treatment was capable of stimulating a 2.5 kb RTP801 promoter. Deletion studies with the promoter demonstrated a critical region between -1057 and -981 bp of the promoter that is responsive to MMS treatment. Point mutations of the consensus Elk-1 and C/EBP sites within this region were able to abrogate the stimulatory effect of MMS, indicating that Elk-1 and C/EBP are both involved in the transcriptional regulation of the RTP801 gene by MMS. Furthermore, a gel mobility shift assay revealed that MMS was able to initiate rapid formation of a protein complex that bound the C/EBP site of the promoter. In addition, an anti-C/EBPbetaantibody was capable of further shifting the bound protein complex. Therefore, these studies indicate that RTP801 is a transcriptional target of MMS in human keratinocytes and that C/EBP is implicated in transcriptional control of the gene.
Lin
Lin
L
Department of Medical and Molecular Genetics, Walther Oncology Center, Indiana University School of Medicine and Walther Cancer Institute, Indianapolis, Indiana 46202, USA.
Qian
Yong
Y
Shi
Xianglin
X
Chen
Yan
Y
D001665:Binding Sites / Q000187:drug effects / Q000235:genetics; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D002461:Cell Line, Transformed; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D008741:Methyl Methanesulfonate / Q000633:toxicity*; D009153:Mutagens / Q000633:toxicity*; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000378:metabolism / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D017384:Sequence Deletion; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D050807:ets-Domain Protein Elk-1
D022762:CCAAT-Enhancer-Binding Proteins; C469991:DDIT4 protein, human; D004268:DNA-Binding Proteins; C494112:ELK1 protein, human; D009153:Mutagens; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D008741:Methyl Methanesulfonate