Biliverdin reductase, a novel regulator for induction of activating transcription factor-2 and heme oxygenase-1.
Biliverdin IXalpha reductase (BVR) catalyzes reduction of the HO activity product, biliverdin, to bilirubin. hBVR is a serine/threonine kinase that contains a bZip domain. Presently, regulation of gene expression by hBVR was examined. 293A cells were infected with adenovirus-doxycycline (Ad-Dox)-inducible hBVR cDNA. High level expression of hBVR was determined at mRNA, protein, and activity levels 8 h after induction. Cell signal transduction microarray analysis of cells infected with expression or with the control Ad-inverted (INV)-hBVR vector identified ATF-2 among several up-regulated genes. ATF-2 is a bZip transcription factor for activation of cAMP response element (CRE) and a dimeric partner to c-jun in MAPK pathway that regulates the stress protein, HO-1, expression. Northern and Western blot analyses showed increases of approximately 10-fold in ATF-2 mRNA and protein at 16 and 24 h after Dox addition. Ad-INV-hBVR did not effect ATF-2 expression. In hBVR-infected cells, levels of HO-1 mRNA and protein were increased. In vitro translated hBVR and nuclear extract containing hBVR in gel mobility-shift assay bound to AP-1 sites in the ATF-2 promoter region and to an oligonucleotide containing the CRE site. Both bindings could be competed out by excess unlabeled probe; in the presence of hBVR antibody, they displayed shifted bands. Co-transfection of hBVR with ATF-2 or c-jun promoters caused a severalfold increase in luciferase activity. hBVR modulation of ATF-2 and HO-1 expression suggests it has a potential role in regulation of AP-1 and cAMP-regulated genes and a role in cell signaling. We propose that increased expression of the protein can be used to alter the gene expression profile in the cell.
Department of Biochemistry and Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Anatoliy
A
Kravets
Zhenbo
Z
Hu
Tihomir
T
Miralem
Michael D
MD
Torno
Mahin D
MD
Maines
D051698:Activating Transcription Factor 2; D000256:Adenoviridae / Q000235:genetics; D020816:Amino Acid Motifs; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D019281:Dimerization; D004318:Doxycycline / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D015971:Gene Expression Regulation, Enzymologic; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008565:Membrane Proteins; D020411:Oligonucleotide Array Sequence Analysis; D009841:Oligonucleotides / Q000737:chemistry; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000502:physiology*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D015854:Up-Regulation
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D008565:Membrane Proteins; D009841:Oligonucleotides; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D014157:Transcription Factors; D000242:Cyclic AMP; D008156:Luciferases; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D044925:Oxidoreductases Acting on CH-CH Group Donors; C019789:biliverdin reductase; D004318:Doxycycline