Functional Genomics Reveals Relationships Between the Retrovirus-Like Ty1 Element and Its Host Saccharomyces cerevisiae

Corresponding author: Scott E. Devine, Emory University School of Medicine, 4133 Rollins Research Center, 1510 Clifton Rd. NE, Atlanta, GA 30322., sedevin{at}emory.edu (E-mail)

Communicating editor: S. SANDMEYER

Retroviruses and their relatives, the long terminal repeat (LTR) retrotransposons, carry out complex life cycles within the cells of their hosts. We have exploited a collection of gene deletion mutants developed by the Saccharomyces Genome Deletion Project to perform a functional genomics screen for host factors that influence the retrovirus-like Ty1 element in yeast. A total of 101 genes that presumably influence many different aspects of the Ty1 retrotransposition cycle were identified from our analysis of 4483 homozygous diploid deletion strains. Of the 101 identified mutants, 46 had significantly altered levels of Ty1 cDNA, whereas the remaining 55 mutants had normal levels of Ty1 cDNA. Thus, approximately half of the mutants apparently affected the early stages of retrotransposition leading up to the assembly of virus-like particles and cDNA replication, whereas the remaining half affected steps that occur after cDNA replication. Although most of the mutants retained the ability to target Ty1 integration to tRNA genes, 2 mutants had reduced levels of tRNA gene targeting. Over 25% of the gene products identified in this study were conserved in other organisms, suggesting that this collection of host factors can serve as a starting point for identifying host factors that influence LTR retroelements and retroviruses in other organisms. Overall, our data indicate that Ty1 requires a large number of cellular host factors to complete its retrotransposition cycle efficiently.

This article has been cited by other articles:

				D. J. Erasmus and H. J.J. van Vuuren Genetic Basis for Osmosensitivity and Genetic Instability of the Wine Yeast Saccharomyces cerevisiae VIN7 Am. J. Enol. Vitic., June 1, 2009; 60(2): 145 - 154. [Abstract] [Full Text] [PDF]

				C. J. Coros, C. L. Piazza, V. R. Chalamcharla, and M. Belfort A mutant screen reveals RNase E as a silencer of group II intron retromobility in Escherichia coli RNA, December 1, 2008; 14(12): 2634 - 2644. [Abstract] [Full Text] [PDF]

				L. M. McLane, K. F. Pulliam, S. E. Devine, and A. H. Corbett The Ty1 integrase protein can exploit the classical nuclear protein import machinery for entry into the nucleus Nucleic Acids Res., August 1, 2008; 36(13): 4317 - 4326. [Abstract] [Full Text] [PDF]

				K. M. Nyswaner, M. A. Checkley, M. Yi, R. M. Stephens, and D. J. Garfinkel Chromatin-Associated Genes Protect the Yeast Genome From Ty1 Insertional Mutagenesis Genetics, January 1, 2008; 178(1): 197 - 214. [Abstract] [Full Text] [PDF]

				M. J. Curcio, A. E. Kenny, S. Moore, D. J. Garfinkel, M. Weintraub, E. R. Gamache, and D. T. Scholes S-Phase Checkpoint Pathways Stimulate the Mobility of the Retrovirus-Like Transposon Ty1 Mol. Cell. Biol., December 15, 2007; 27(24): 8874 - 8885. [Abstract] [Full Text] [PDF]

				E. D. Pratico and S. K. Silverman Ty1 reverse transcriptase does not read through the proposed 2',5'-branched retrotransposition intermediate in vitro RNA, September 1, 2007; 13(9): 1528 - 1536. [Abstract] [Full Text] [PDF]

				P. H. Maxwell and M. J. Curcio Host Factors That Control Long Terminal Repeat Retrotransposons in Saccharomyces cerevisiae: Implications for Regulation of Mammalian Retroviruses Eukaryot. Cell, July 1, 2007; 6(7): 1069 - 1080. [Full Text] [PDF]

				D. J. Garfinkel, K. M. Stefanisko, K. M. Nyswaner, S. P. Moore, J. Oh, and S. H. Hughes Retrotransposon Suicide: Formation of Ty1 Circles and Autointegration via a Central DNA Flap J. Virol., December 15, 2006; 80(24): 11920 - 11934. [Abstract] [Full Text] [PDF]

				S. L. Sawyer and H. S. Malik Eukaryotic Transposable Elements and Genome Evolution Special Feature: Positive selection of yeast nonhomologous end-joining genes and a retrotransposon conflict hypothesis PNAS, November 21, 2006; 103(47): 17614 - 17619. [Abstract] [Full Text] [PDF]

				Z. Mou, A. E. Kenny, and M. J. Curcio Hos2 and Set3 Promote Integration of Ty1 Retrotransposons at tRNA Genes in Saccharomyces cerevisiae Genetics, April 1, 2006; 172(4): 2157 - 2167. [Abstract] [Full Text] [PDF]

				N. BELIAKOVA-BETHELL, C. BECKHAM, T. H. GIDDINGS JR, M. WINEY, R. PARKER, and S. SANDMEYER Virus-like particles of the Ty3 retrotransposon assemble in association with P-body components RNA, January 1, 2006; 12(1): 94 - 101. [Abstract] [Full Text] [PDF]

				E. R. Havecker, X. Gao, and D. F. Voytas The Sireviruses, a Plant-Specific Lineage of the Ty1/copia Retrotransposons, Interact with a Family of Proteins Related to Dynein Light Chain 8 Plant Physiology, October 1, 2005; 139(2): 857 - 868. [Abstract] [Full Text] [PDF]

				B. Irwin, M. Aye, P. Baldi, N. Beliakova-Bethell, H. Cheng, Y. Dou, W. Liou, and S. Sandmeyer Retroviruses and yeast retrotransposons use overlapping sets of host genes Genome Res., May 1, 2005; 15(5): 641 - 654. [Abstract] [Full Text] [PDF]

				D. J. Garfinkel, K. M. Nyswaner, K. M. Stefanisko, C. Chang, and S. P. Moore Ty1 Copy Number Dynamics in Saccharomyces Genetics, April 1, 2005; 169(4): 1845 - 1857. [Abstract] [Full Text] [PDF]

				M. Aye, B. Irwin, N. Beliakova-Bethell, E. Chen, J. Garrus, and S. Sandmeyer Host Factors That Affect Ty3 Retrotransposition in Saccharomyces cerevisiae Genetics, November 1, 2004; 168(3): 1159 - 1176. [Abstract] [Full Text] [PDF]

				N. Bachman, Y. Eby, and J. D. Boeke Local Definition of Ty1 Target Preference by Long Terminal Repeats and Clustered tRNA Genes Genome Res., July 1, 2004; 14(7): 1232 - 1247. [Abstract] [Full Text] [PDF]