Abstract
Several cDNA clones representing alternatively spliced Rev-specific transcripts were isolated from a cDNA library prepared from Himalayan tahr cells infected with caprine arthritis encephalitis virus (CAEV). We previously characterized two rev-like cDNA species, d1 and d2, and a tat e1 cDNA containing the rev coding sequence downstream to the tat. In these cDNAs, the rev coding domain derives its amino terminus from the N terminus of env, which is spliced to the 3' open reading frame encoding the putative Rev protein. In this study, we report the genetic structure of a fourth rev-like cDNA (designated g1), which lacks the 5' env-derived sequences. All of these rev transcripts, including cDNA g1, increased the level of chloramphenicol acetyltransferase expression when cotransfected with a reporter plasmid containing the CAEV Rev-response element-spanning region downstream of the cat coding sequences. Western blot (immunoblot) analysis showed that each transfected cDNA species gave rise to a 16-kDa protein lacking env-encoded amino-terminal epitopes. In contrast, CAEV-infected Himalayan tahr cells expressed only a 20-kDa protein, whose N terminus, in contrast, is derived from the env. Moreover, only the 20-kDa protein was also detected in the mature CAEV virions. These observations suggest that the transcripts d1, d2, and e1 can potentially, in appropriate cellular context, encode two Rev isoforms differing in their N termini, whereas the g1 transcript encodes only the 16-kDa species. Elucidation of the significance of the 16-kDa Rev protein in CAEV biology must await further studies.
Full Text
The Full Text of this article is available as a PDF (267.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Acland P., Dixon M., Peters G., Dickson C. Subcellular fate of the int-2 oncoprotein is determined by choice of initiation codon. Nature. 1990 Feb 15;343(6259):662–665. doi: 10.1038/343662a0. [DOI] [PubMed] [Google Scholar]
- Antoni B. A., Stein S. B., Rabson A. B. Regulation of human immunodeficiency virus infection: implications for pathogenesis. Adv Virus Res. 1994;43:53–145. doi: 10.1016/s0065-3527(08)60047-0. [DOI] [PubMed] [Google Scholar]
- Bugler B., Amalric F., Prats H. Alternative initiation of translation determines cytoplasmic or nuclear localization of basic fibroblast growth factor. Mol Cell Biol. 1991 Jan;11(1):573–577. doi: 10.1128/mcb.11.1.573. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Davis J. L., Clements J. E. Characterization of a cDNA clone encoding the visna virus transactivating protein. Proc Natl Acad Sci U S A. 1989 Jan;86(2):414–418. doi: 10.1073/pnas.86.2.414. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kalinski H., Mashiah P., Rotem D., Orzech Y., Sherman L., Miki T., Yaniv A., Gazit A., Tronick S. R. Characterization of cDNAs species encoding the Tat protein of caprine arthritis encephalitis virus. Virology. 1994 Nov 1;204(2):828–834. doi: 10.1006/viro.1994.1602. [DOI] [PubMed] [Google Scholar]
- Kalinski H., Yaniv A., Mashiah P., Miki T., Tronick S. R., Gazit A. rev-like transcripts of caprine arthritis encephalitis virus. Virology. 1991 Aug;183(2):786–792. doi: 10.1016/0042-6822(91)91012-6. [DOI] [PubMed] [Google Scholar]
- Kozak M. Adherence to the first-AUG rule when a second AUG codon follows closely upon the first. Proc Natl Acad Sci U S A. 1995 Mar 28;92(7):2662–2666. doi: 10.1073/pnas.92.7.2662. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kozak M. Effects of intercistronic length on the efficiency of reinitiation by eucaryotic ribosomes. Mol Cell Biol. 1987 Oct;7(10):3438–3445. doi: 10.1128/mcb.7.10.3438. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mazarin V., Gourdou I., Querat G., Sauze N., Audoly G., Vitu C., Russo P., Rousselot C., Filippi P., Vigne R. Subcellular localization of rev-gene product in visna virus-infected cells. Virology. 1990 Sep;178(1):305–310. doi: 10.1016/0042-6822(90)90410-s. [DOI] [PubMed] [Google Scholar]
- Mazarin V., Gourdou I., Quérat G., Sauze N., Vigne R. Genetic structure and function of an early transcript of visna virus. J Virol. 1988 Dec;62(12):4813–4818. doi: 10.1128/jvi.62.12.4813-4818.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oberste M. S., Greenwood J. D., Gonda M. A. Analysis of the transcription pattern and mapping of the putative rev and env splice junctions of bovine immunodeficiency-like virus. J Virol. 1991 Jul;65(7):3932–3937. doi: 10.1128/jvi.65.7.3932-3937.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oberste M. S., Williamson J. C., Greenwood J. D., Nagashima K., Copeland T. D., Gonda M. A. Characterization of bovine immunodeficiency virus rev cDNAs and identification and subcellular localization of the Rev protein. J Virol. 1993 Nov;67(11):6395–6405. doi: 10.1128/jvi.67.11.6395-6405.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Phillips T. R., Lamont C., Konings D. A., Shacklett B. L., Hamson C. A., Luciw P. A., Elder J. H. Identification of the Rev transactivation and Rev-responsive elements of feline immunodeficiency virus. J Virol. 1992 Sep;66(9):5464–5471. doi: 10.1128/jvi.66.9.5464-5471.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rosin-Arbesfeld R., Rivlin M., Noiman S., Mashiah P., Yaniv A., Miki T., Tronick S. R., Gazit A. Structural and functional characterization of rev-like transcripts of equine infectious anemia virus. J Virol. 1993 Sep;67(9):5640–5646. doi: 10.1128/jvi.67.9.5640-5646.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Saltarelli M. J., Schoborg R., Gdovin S. L., Clements J. E. The CAEV tat gene trans-activates the viral LTR and is necessary for efficient viral replication. Virology. 1993 Nov;197(1):35–44. doi: 10.1006/viro.1993.1564. [DOI] [PubMed] [Google Scholar]
- Saltarelli M. J., Schoborg R., Pavlakis G. N., Clements J. E. Identification of the caprine arthritis encephalitis virus Rev protein and its cis-acting Rev-responsive element. Virology. 1994 Feb 15;199(1):47–55. doi: 10.1006/viro.1994.1096. [DOI] [PubMed] [Google Scholar]
- Saltarelli M., Querat G., Konings D. A., Vigne R., Clements J. E. Nucleotide sequence and transcriptional analysis of molecular clones of CAEV which generate infectious virus. Virology. 1990 Nov;179(1):347–364. doi: 10.1016/0042-6822(90)90303-9. [DOI] [PubMed] [Google Scholar]
- Schoborg R. V., Clements J. E. The Rev protein of visna virus is localized to the nucleus of infected cells. Virology. 1994 Jul;202(1):485–490. doi: 10.1006/viro.1994.1367. [DOI] [PubMed] [Google Scholar]
- Schoborg R. V., Saltarelli M. J., Clements J. E. A Rev protein is expressed in caprine arthritis encephalitis virus (CAEV)-infected cells and is required for efficient viral replication. Virology. 1994 Jul;202(1):1–15. doi: 10.1006/viro.1994.1316. [DOI] [PubMed] [Google Scholar]
- Schwartz S., Felber B. K., Pavlakis G. N. Mechanism of translation of monocistronic and multicistronic human immunodeficiency virus type 1 mRNAs. Mol Cell Biol. 1992 Jan;12(1):207–219. doi: 10.1128/mcb.12.1.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spence A. M., Sheppard P. C., Davie J. R., Matuo Y., Nishi N., McKeehan W. L., Dodd J. G., Matusik R. J. Regulation of a bifunctional mRNA results in synthesis of secreted and nuclear probasin. Proc Natl Acad Sci U S A. 1989 Oct;86(20):7843–7847. doi: 10.1073/pnas.86.20.7843. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Unger R. E., Stout M. W., Luciw P. A. Simian immunodeficiency virus (SIVmac) exhibits complex splicing for tat, rev, and env mRNA. Virology. 1991 May;182(1):177–185. doi: 10.1016/0042-6822(91)90661-t. [DOI] [PubMed] [Google Scholar]
- Viglianti G. A., Sharma P. L., Mullins J. I. Simian immunodeficiency virus displays complex patterns of RNA splicing. J Virol. 1990 Sep;64(9):4207–4216. doi: 10.1128/jvi.64.9.4207-4216.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wain-Hobson S., Sonigo P., Guyader M., Gazit A., Henry M. Erratic G-->A hypermutation within a complete caprine arthritis-encephalitis virus (CAEV) provirus. Virology. 1995 Jun 1;209(2):297–303. doi: 10.1006/viro.1995.1261. [DOI] [PubMed] [Google Scholar]
- Yaniv A., Dahlberg J. E., Tronick S. R., Chiu I. M., Aaronson S. A. Molecular cloning of integrated caprine arthritis-encephalitis virus. Virology. 1985 Sep;145(2):340–345. doi: 10.1016/0042-6822(85)90169-2. [DOI] [PubMed] [Google Scholar]