Abstract
Cytochrome P-450 monooxygenases (P-450s) play a critical role in the detoxification of natural and synthetic toxins in a wide range of organisms. We have isolated and sequenced cDNA clones encoding a P-450, CYP6B1, from larvae of Papilio polyxenes (Lepidoptera: Papilionidae), the black swallowtail butterfly. This P-450, cloned from a herbivorous insect, is highly inducible by xanthotoxin, a secondary metabolite abundant in the host plants of this specialized herbivore. On Northern blots, mRNAs crossreactive with CYP6B1 were detected in three Papilio species that, like the black swallowtail, have high levels of xanthotoxin-metabolic P-450 activity and encounter xanthotoxin or related compounds in their host plants; in contrast, no crossreactive mRNAs were detectable in three papilinid species that never encounter xanthotoxin in their host plants and lack detectable xanthotoxin-metabolic activity. These results provide evidence that new P-450s can arise as herbivores colonize different host plants and support the hypothesis that interactions between herbivores and their toxin-producing host plants have contributed to the diversification of the P-450 superfamily.
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- Berenbaum M. Toxicity of a furanocoumarin to armyworms: a case of biosynthetic escape from insect herbivores. Science. 1978 Aug 11;201(4355):532–534. doi: 10.1126/science.201.4355.532. [DOI] [PubMed] [Google Scholar]
- Feyereisen R., Koener J. F., Farnsworth D. E., Nebert D. W. Isolation and sequence of cDNA encoding a cytochrome P-450 from an insecticide-resistant strain of the house fly, Musca domestica. Proc Natl Acad Sci U S A. 1989 Mar;86(5):1465–1469. doi: 10.1073/pnas.86.5.1465. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fyrberg E. A., Kindle K. L., Davidson N., Kindle K. L. The actin genes of Drosophila: a dispersed multigene family. Cell. 1980 Feb;19(2):365–378. doi: 10.1016/0092-8674(80)90511-5. [DOI] [PubMed] [Google Scholar]
- Gonzalez F. J., Nebert D. W. Evolution of the P450 gene superfamily: animal-plant 'warfare', molecular drive and human genetic differences in drug oxidation. Trends Genet. 1990 Jun;6(6):182–186. doi: 10.1016/0168-9525(90)90174-5. [DOI] [PubMed] [Google Scholar]
- Gonzalez F. J. The molecular biology of cytochrome P450s. Pharmacol Rev. 1988 Dec;40(4):243–288. [PubMed] [Google Scholar]
- Ivie G. W., Bull D. L., Beier R. C., Pryor N. W., Oertli E. H. Metabolic detoxification: mechanism of insect resistance to plant psoralens. Science. 1983 Jul 22;221(4608):374–376. doi: 10.1126/science.221.4608.374. [DOI] [PubMed] [Google Scholar]
- Johnson E. F., Kronbach T., Hsu M. H. Analysis of the catalytic specificity of cytochrome P450 enzymes through site-directed mutagenesis. FASEB J. 1992 Jan 6;6(2):700–705. doi: 10.1096/fasebj.6.2.1537459. [DOI] [PubMed] [Google Scholar]
- Nebert D. W., Gonzalez F. J. P450 genes: structure, evolution, and regulation. Annu Rev Biochem. 1987;56:945–993. doi: 10.1146/annurev.bi.56.070187.004501. [DOI] [PubMed] [Google Scholar]
- Nebert D. W., Nelson D. R., Coon M. J., Estabrook R. W., Feyereisen R., Fujii-Kuriyama Y., Gonzalez F. J., Guengerich F. P., Gunsalus I. C., Johnson E. F. The P450 superfamily: update on new sequences, gene mapping, and recommended nomenclature. DNA Cell Biol. 1991 Jan-Feb;10(1):1–14. doi: 10.1089/dna.1991.10.1. [DOI] [PubMed] [Google Scholar]
- Nelson D. R., Strobel H. W. Evolution of cytochrome P-450 proteins. Mol Biol Evol. 1987 Nov;4(6):572–593. doi: 10.1093/oxfordjournals.molbev.a040471. [DOI] [PubMed] [Google Scholar]