Abstract
Mutations surrounding the first methionine codon of the E5 transforming gene of bovine papillomavirus (type 1) were analyzed for their effect on cellular transformation and on the synthesis of the 7-kd E5 polypeptide. Frameshift mutations upstream of this methionine codon (bp 3879) affect neither transforming activity nor the ability to synthesize full-size E5 protein. In contrast, frameshift mutations distal to this position result in the inhibition of cell transformation and prevent synthesis or accumulation of E5 protein in cells containing the mutant viral genomes. Several in-frame mutations distal to the first methionine codon have a minimal effect on transforming activity but alter the electrophoretic mobility of the E5 protein in a manner consistent with the generated genetic alteration (deletion, insertion or substitution). In all cases where the protein is detected, it fractionates with cellular membranes and forms dimers. These studies indicate that (i) the methionine codon at bp 3879 serves as the initiation codon for the mature E5 protein, (ii) changing the charge of the E5 amino-terminus (from neutral to positive) does not prevent the association of this hydrophobic polypeptide with cellular membranes, and (iii) E5 amino-terminal mutations do not interfere with the ability of this polypeptide to form homodimers. We conclude that the major focus-inducing activity of the intact BPV genome is due to the function of the small polypeptide encoded in the 3' half of the E5 ORF.
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- Colbère-Garapin F., Horodniceanu F., Kourilsky P., Garapin A. C. A new dominant hybrid selective marker for higher eukaryotic cells. J Mol Biol. 1981 Jul 25;150(1):1–14. doi: 10.1016/0022-2836(81)90321-1. [DOI] [PubMed] [Google Scholar]
- DiMaio D., Guralski D., Schiller J. T. Translation of open reading frame E5 of bovine papillomavirus is required for its transforming activity. Proc Natl Acad Sci U S A. 1986 Mar;83(6):1797–1801. doi: 10.1073/pnas.83.6.1797. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DiMaio D., Treisman R., Maniatis T. Bovine papillomavirus vector that propagates as a plasmid in both mouse and bacterial cells. Proc Natl Acad Sci U S A. 1982 Jul;79(13):4030–4034. doi: 10.1073/pnas.79.13.4030. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dvoretzky I., Shober R., Chattopadhyay S. K., Lowy D. R. A quantitative in vitro focus assay for bovine papilloma virus. Virology. 1980 Jun;103(2):369–375. doi: 10.1016/0042-6822(80)90195-6. [DOI] [PubMed] [Google Scholar]
- Groff D. E., Lancaster W. D. Genetic analysis of the 3' early region transformation and replication functions of bovine papillomavirus type 1. Virology. 1986 Apr 15;150(1):221–230. doi: 10.1016/0042-6822(86)90281-3. [DOI] [PubMed] [Google Scholar]
- Kozak M. Compilation and analysis of sequences upstream from the translational start site in eukaryotic mRNAs. Nucleic Acids Res. 1984 Jan 25;12(2):857–872. doi: 10.1093/nar/12.2.857. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sarver N., Rabson M. S., Yang Y. C., Byrne J. C., Howley P. M. Localization and analysis of bovine papillomavirus type 1 transforming functions. J Virol. 1984 Nov;52(2):377–388. doi: 10.1128/jvi.52.2.377-388.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schiller J. T., Vass W. C., Lowy D. R. Identification of a second transforming region in bovine papillomavirus DNA. Proc Natl Acad Sci U S A. 1984 Dec;81(24):7880–7884. doi: 10.1073/pnas.81.24.7880. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schiller J. T., Vass W. C., Vousden K. H., Lowy D. R. E5 open reading frame of bovine papillomavirus type 1 encodes a transforming gene. J Virol. 1986 Jan;57(1):1–6. doi: 10.1128/jvi.57.1.1-6.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schlegel R., Benjamin T. L. Cellular alterations dependent upon the polyoma virus Hr-t function: separation of mitogenic from transforming capacities. Cell. 1978 Jul;14(3):587–599. doi: 10.1016/0092-8674(78)90244-1. [DOI] [PubMed] [Google Scholar]
- Schlegel R., Wade-Glass M., Rabson M. S., Yang Y. C. The E5 transforming gene of bovine papillomavirus encodes a small, hydrophobic polypeptide. Science. 1986 Jul 25;233(4762):464–467. doi: 10.1126/science.3014660. [DOI] [PubMed] [Google Scholar]
- Southern P. J., Berg P. Transformation of mammalian cells to antibiotic resistance with a bacterial gene under control of the SV40 early region promoter. J Mol Appl Genet. 1982;1(4):327–341. [PubMed] [Google Scholar]
- Yang Y. C., Okayama H., Howley P. M. Bovine papillomavirus contains multiple transforming genes. Proc Natl Acad Sci U S A. 1985 Feb;82(4):1030–1034. doi: 10.1073/pnas.82.4.1030. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yang Y. C., Spalholz B. A., Rabson M. S., Howley P. M. Dissociation of transforming and trans-activation functions for bovine papillomavirus type 1. Nature. 1985 Dec 12;318(6046):575–577. doi: 10.1038/318575a0. [DOI] [PubMed] [Google Scholar]