Host factors that affect Ty3 retrotransposition in Saccharomyces cerevisiae.
The retrovirus-like element Ty3 of Saccharomyces cerevisiae integrates at the transcription initiation region of RNA polymerase III. To identify host genes that affect transposition, a collection of insertion mutants was screened using a genetic assay in which insertion of Ty3 activates expression of a tRNA suppressor. Fifty-three loci were identified in this screen. Corresponding knockout mutants were tested for the ability to mobilize a galactose-inducible Ty3, marked with the HIS3 gene. Of 42 mutants tested, 22 had phenotypes similar to those displayed in the original assay. The proteins encoded by the defective genes are involved in chromatin dynamics, transcription, RNA processing, protein modification, cell cycle regulation, nuclear import, and unknown functions. These mutants were induced for Ty3 expression and assayed for Gag3p protein, integrase, cDNA, and Ty3 integration upstream of chromosomal tDNA(Val(AAC)) genes. Most mutants displayed differences from the wild type in one or more intermediates, although these were typically not as severe as the genetic defect. Because a relatively large number of genes affecting retrotransposition can be identified in yeast and because the majority of these genes have mammalian homologs, this approach provides an avenue for the identification of potential antiviral targets.
Aye
Michael
M
Department of Biological Chemistry, University of California College of Medicine, Irvine, California 92697, USA.
Irwin
Becky
B
Beliakova-Bethell
Nadejda
N
Chen
Eric
E
Garrus
Jennifer
J
Sandmeyer
Suzanne
S
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D018076:DNA, Complementary; D009154:Mutation; D012366:RNA, Transfer, Val / Q000235:genetics; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D011995:Recombination, Genetic / Q000502:physiology*; D018626:Retroelements; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; C429283:MDV1 protein, S cerevisiae; D012366:RNA, Transfer, Val; D018626:Retroelements; D029701:Saccharomyces cerevisiae Proteins; D012194:RNA-Directed DNA Polymerase; C496084:reverse transcriptase Ty3, S cerevisiae