title: Constitutive and xenobiotics-induced expression of a novel CYP3A gene from zebrafish larva.
abstract: In mammals, CYP3A isozymes collectively comprise the largest portion of the liver and small intestinal CYP protein. They are involved in the metabolism of an extensive range of endogenous substrates and xenobiotics and make a significant contribution to the termination of the action of steroid hormones. A full-length cDNA of CYP3A gene, named CYP3A65, was cloned from zebrafish by RT-PCR. The CYP3A65 mRNA was initially transcribed only in the liver and intestine upon hatching of the zebrafish embryos. Like the human CYP3A genes, CYP3A65 transcription in the foregut region was enhanced by treatment of the zebrafish larvae with the steroid dexamethasone and the macrocyclic antibiotic rifampicin. Differing from mammalian CYP3A genes, CYP3A65 transcription was also elicited by 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) during early larval stages. Repression of AHR2 translation by antisense morpholino oligonucleotides abrogated both of constitutive and TCDD-stimulated CYP3A65 transcription in larval intestine. These findings suggested that the AHR2 signaling pathway plays an essential role in CYP3A65 transcription.
authors.affiliation: Department of Life Science, National Tsing-Hua University, Hsinchu, Taiwan.
authors.forename: Hua-Pin
authors.initials: HP
authors.lastname: Tseng
authors.forename: Tzong-Hsiung
authors.initials: TH
authors.lastname: Hseu
authors.forename: Donald R
authors.initials: DR
authors.lastname: Buhler
authors.forename: Wen-Der
authors.initials: WD
authors.lastname: Wang
authors.forename: Chin-Hwa
authors.initials: CH
authors.lastname: Hu
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects* / Q000235:genetics; D017403:In Situ Hybridization / Q000379:methods; D007422:Intestines / Q000187:drug effects / Q000196:embryology; D007814:Larva / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010089:Oxidoreductases, N-Demethylating / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000037:antagonists & inhibitors / Q000494:pharmacology; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon / Q000037:antagonists & inhibitors / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012293:Rifampin / Q000494:pharmacology; D020539:Sequence Analysis, Protein / Q000379:methods; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D015262:Xenobiotics / Q000737:chemistry / Q000494:pharmacology*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism
chemical_list: C474372:AHR2 protein, zebrafish; D016376:Oligonucleotides, Antisense; D000072317:Polychlorinated Dibenzodioxins; D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D015262:Xenobiotics; D029961:Zebrafish Proteins; D003907:Dexamethasone; D001189:Aryl Hydrocarbon Hydroxylases; C502466:cytochrome P-450 CYP3A65, zebrafish; D010089:Oxidoreductases, N-Demethylating; D012293:Rifampin