Pescadillo interacts with the cadmium response element of the human heme oxygenase-1 promoter in renal epithelial cells.
Renal tubular cells elicit adaptive responses following exposure to nephrotoxins, such as cadmium. One response is the up-regulation of the 32-kDa redox-sensitive protein, heme oxygenase-1. Exposure of renal proximal tubular epithelial cells to 10 mum cadmium demonstrated induction ( approximately 20-fold) of heme oxygenase-1 mRNA and protein. Using a 4.5-kb human heme oxygenase-1 promoter construct, the importance of a previously identified cadmium response element (TGCTAGAT) in HeLa cells was verified in renal epithelial cells. Specific protein-DNA interaction with this sequence was demonstrated using nuclear extracts from cadmium-treated cells. Yeast one-hybrid screen of a human kidney cDNA library resulted in the identification of pescadillo, a unique nucleolar, developmental protein, as an interacting protein with the cadmium response element and was confirmed by chromatin immunoprecipitation in vivo and gel shift assays with purified glutathione S-transferase-pescadillo protein in vitro. The specificity of the DNA-protein interaction was verified by the absence of a binding complex when the core sequence of the cadmium response element was mutated or deleted. In addition, B23/nucleophosmin, another nucleolar protein, did not interact with the cadmium response sequence. Overexpression of pescadillo resulted in increased activity of the 4.5-kb human heme oxygenase-1 promoter construct but failed to activate this construct when the cadmium response sequence was mutated. The findings demonstrate the important and previously unrecognized role of pescadillo as a DNA-binding protein interacting specifically with the cadmium response element of the human heme oxygenase-1 gene.
Sikorski
Eric M
EM
Division of Nephrology, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Uo
Takuma
T
Morrison
Richard S
RS
Agarwal
Anupam
A
D001483:Base Sequence; D001665:Binding Sites; D002104:Cadmium / Q000378:metabolism* / Q000494:pharmacology; D002461:Cell Line, Transformed; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D004847:Epithelial Cells / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007684:Kidney Tubules / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins
D004268:DNA-Binding Proteins; C484463:PES1 protein, human; D011506:Proteins; D016601:RNA-Binding Proteins; D002104:Cadmium; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1