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.
Kravets
Anatoliy
A
Department of Biochemistry and Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Hu
Zhenbo
Z
Miralem
Tihomir
T
Torno
Michael D
MD
Maines
Mahin D
MD
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