This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hansen, L J Articles by Sandmeyer, S B Search for Related Content PubMed PubMed Citation Articles by Hansen, L J Articles by Sandmeyer, S B

Ty3 GAG3 and POL3 genes encode the components of intracellular particles.

Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine 92717.

ABSTRACT

Ty3 is a Saccharomyces cerevisiae retrotransposon that integrates near the transcription initiation sites of polymerase III-transcribed genes. It is distinct from the copialike Ty1 and Ty2 retrotransposons of S. cerevisiae in both the sequences of encoded proteins and gene order. It is a member of the gypsylike family of retrotransposons which resemble animal retroviruses. This study was undertaken to investigate the nucleocapsid particle of a transpositionally active gypsylike retrotransposon. Characterization of extracts from cells in which Ty3 expression was induced showed the presence of Ty3 nucleoprotein complexes, or viruslike particles, that migrated on linear sucrose gradients with a size of 156S. These particles are composed of Ty3 RNA, full-length, linear DNA, and proteins. In this study, antibodies raised against peptides predicted from the Ty3 sequence were used to identify Ty3-encoded proteins. These include the capsid (26 kDa), nucleocapsid (9 kDa), and reverse transcriptase (55 kDa) proteins. Ty3 integrase proteins of 61 and 58 kDa were identified previously (L. J. Hansen and S. B. Sandmeyer, J. Virol. 64:2599-2607, 1990). Reverse transcriptase activity associated with the particles was measured by using exogenous and endogenous primer-templates. Immunofluorescence studies of cells overexpressing Ty3 revealed cytoplasmic clusters of immunoreactive proteins. Transmission electron microscopy showed that Ty3 viruslike particles are about 50 nm in diameter. Thus, despite the unusual position specificity of Ty3 upstream of tRNA-coding regions, aspects of the Ty3 life cycle are fundamentally similar to those of retroviruses.

This article has been cited by other articles:

• Larsen, L. S. Z., Beliakova-Bethell, N., Bilanchone, V., Zhang, M., Lamsa, A., DaSilva, R., Hatfield, G. W., Nagashima, K., Sandmeyer, S. (2008). Ty3 Nucleocapsid Controls Localization of Particle Assembly. J. Virol. 82: 2501-2514 [Abstract] [Full Text]  
• Larsen, L. S. Z., Zhang, M., Beliakova-Bethell, N., Bilanchone, V., Lamsa, A., Nagashima, K., Najdi, R., Kosaka, K., Kovacevic, V., Cheng, J., Baldi, P., Hatfield, G. W., Sandmeyer, S. (2007). Ty3 Capsid Mutations Reveal Early and Late Functions of the Amino-Terminal Domain. J. Virol. 81: 6957-6972 [Abstract] [Full Text]  
• BELIAKOVA-BETHELL, N., BECKHAM, C., GIDDINGS, T. H. JR, WINEY, M., PARKER, R., SANDMEYER, S. (2006). Virus-like particles of the Ty3 retrotransposon assemble in association with P-body components. RNA 12: 94-101 [Abstract] [Full Text]  
• Kuznetsov, Y. G., Zhang, M., Menees, T. M., McPherson, A., Sandmeyer, S. (2005). Investigation by Atomic Force Microscopy of the Structure of Ty3 Retrotransposon Particles. J. Virol. 79: 8032-8045 [Abstract] [Full Text]  
• Irwin, B., Aye, M., Baldi, P., Beliakova-Bethell, N., Cheng, H., Dou, Y., Liou, W., Sandmeyer, S. (2005). Retroviruses and yeast retrotransposons use overlapping sets of host genes. Genome Res. 15: 641-654 [Abstract] [Full Text]  
• Aye, M., Irwin, B., Beliakova-Bethell, N., Chen, E., Garrus, J., Sandmeyer, S. (2004). Host Factors That Affect Ty3 Retrotransposition in Saccharomyces cerevisiae. Genetics 168: 1159-1176 [Abstract] [Full Text]  
• Teysset, L., Dang, V.-D., Kim, M. K., Levin, H. L. (2003). A Long Terminal Repeat-Containing Retrotransposon of Schizosaccharomyces pombe Expresses a Gag-Like Protein That Assembles into Virus-Like Particles Which Mediate Reverse Transcription. J. Virol. 77: 5451-5463 [Abstract] [Full Text]  
• Yieh, L., Hatzis, H., Kassavetis, G., Sandmeyer, S. B. (2002). Mutational Analysis of the Transcription Factor IIIB-DNA Target of Ty3 Retroelement Integration. J. Biol. Chem. 277: 25920-25928 [Abstract] [Full Text]  
• Lener, D., Budihas, S. R., Le Grice, S. F. J. (2002). Mutating Conserved Residues in the Ribonuclease H Domain of Ty3 Reverse Transcriptase Affects Specialized Cleavage Events. J. Biol. Chem. 277: 26486-26495 [Abstract] [Full Text]  
• Nymark-McMahon, M. H., Beliakova-Bethell, N. S., Darlix, J.-L., Le Grice, S. F. J., Sandmeyer, S. B. (2002). Ty3 Integrase Is Required for Initiation of Reverse Transcription. J. Virol. 76: 2804-2816 [Abstract] [Full Text]  
• Lin, S. S., Nymark-McMahon, M. H., Yieh, L., Sandmeyer, S. B. (2001). Integrase Mediates Nuclear Localization of Ty3. Mol. Cell. Biol. 21: 7826-7838 [Abstract] [Full Text]  
• Irwin, P. A., Voytas, D. F. (2001). Expression and Processing of Proteins Encoded by the Saccharomyces Retrotransposon Ty5. J. Virol. 75: 1790-1797 [Abstract] [Full Text]  
• Claypool, J. A., Malik, H. S., Eickbush, T. H., Sandmeyer, S. B. (2001). Ten-Kilodalton Domain in Ty3 Gag3-Pol3p between PR and RT Is Dispensable for Ty3 Transposition. J. Virol. 75: 1557-1560 [Abstract] [Full Text]  
• Rausch, J. W., Grice, M. K. B.-L., Henrietta, M., Nymark-McMahon, , Miller, J. T., Le Grice, S. F. J. (2000). Interaction of p55 Reverse Transcriptase from the Saccharomyces cerevisiae Retrotransposon Ty3 with Conformationally Distinct Nucleic Acid Duplexes. J. Biol. Chem. 275: 13879-13887 [Abstract] [Full Text]  
• Nymark-McMahon, M. H., Sandmeyer, S. B. (1999). Mutations in Nonconserved Domains of Ty3 Integrase Affect Multiple Stages of the Ty3 Life Cycle. J. Virol. 73: 453-465 [Abstract] [Full Text]  
• Hajek, K. L., Friesen, P. D. (1998). Proteolytic Processing and Assembly of gag and gag-pol Proteins of TED, a Baculovirus-Associated Retrotransposon of the Gypsy Family. J. Virol. 72: 8718-8724 [Abstract] [Full Text]  
• Farabaugh, P. J., Farabaugh, P. J. (1995). Post-transcriptional Regulation of Transposition by Ty Retrotransposons of Saccharomyces cerevisiae. J. Biol. Chem. 270: 10361-10364 [Full Text]  
• Kirchner, J, Connolly, C., Sandmeyer, S. (1995). Requirement of RNA polymerase III transcription factors for in vitro position-specific integration of a retroviruslike element. Science 267: 1488-1491 [Abstract]  
• Yieh, L., Kassavetis, G., Geiduschek, E. P., Sandmeyer, S. B. (2000). The Brf and TATA-binding Protein Subunits of the RNA Polymerase III Transcription Factor IIIB Mediate Position-specific Integration of the Gypsy-like Element, Ty3. J. Biol. Chem. 275: 29800-29807 [Abstract] [Full Text]