Transcription of the rat liver uricase-encoding gene is regulated via a cis-acting element responsive to cAMP.
Glucagon was found to increase the mRNA level of the uricase-encoding gene (UOX), but not that of genes encoding other peroxisomal enzymes, such as catalase, acyl-CoA oxidase and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase. The possible involvement of cAMP in the glucagon-induced transcription of rat UOX was studied by measuring the enhancer activity of the isolated 5'-untranslated region of the gene. An 84-bp sequence spanning positions -169 to -86 was found to be essential for cAMP-mediated expression of rat UOX, on deletional analysis of the upstream 1.4-kb portion by means of a transient transfection assay (CAT assay). The 30-mer oligodeoxyribonucleotide (positions from -169 to -140) was found to form a DNA-protein complex by an electrophoretic mobility shift assay. The core sequence for the DNA-protein complex formation, 5'-CAAAAATGTC-3', was found to be located in positions from -164 to -155. In addition, the binding assays suggested that the DNA-binding protein(s) was different from cAMP-response element binding protein (CREB). Thus, this report shows that a novel cis-acting element of rat UOX and the binding protein(s) possibly play an essential role in the glucagon-induced transcription via cAMP.
Izuhara
M
M
Department of Biology, Saga Medical School, Japan.
Ito
M
M
Takagi
Y
Y
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D005934:Glucagon / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D015398:Signal Transduction; D014158:Transcription, Genetic; D014503:Urate Oxidase / Q000235:genetics*
D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D005934:Glucagon; D000242:Cyclic AMP; D014503:Urate Oxidase