Inhibition of Ty1 transposition by mating pheromones in Saccharomyces cerevisiae.
The Ty1 elements in the yeast Saccharomyces cerevisiae are a family of retrotransposons which transpose via a process similar to that of retroviral replication. We report here that the Ty1 transposition process can be blocked posttranscriptionally by treatment of cells with mating pheromones. When haploid yeast cells are treated with appropriate mating pheromones, the transposition frequency of a marked Ty1 element driven by the GAL1 promoter is greatly diminished. Ty1 viruslike particles (VLPs), the putative intermediates for transposition, can be isolated from mating pheromone-treated cells. These VLPs accumulate to normal levels but are aberrant in that they produce very few reverse transcripts of Ty1 RNA both in vivo and in vitro and contain subnormal amounts of p90-TYB and related proteins. In addition, a TYA phosphoprotein product accumulates in treated cells, and some species of TYB proteins have decreased stability. We also show that decreased transposition in mating pheromone-treated cells is not a consequence of simply blocking cell division, since Ty1 transposes at a nearly normal rate in yeast cells arrested in G2 by the drug nocodazole.
Xu
H
H
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Boeke
J D
JD
D004251:DNA Transposable Elements / Q000187:drug effects; D005656:Fungal Proteins / Q000235:genetics* / Q000302:isolation & purification; D006238:Haploidy; D000072235:Mating Factor; D008970:Molecular Weight; D015739:Nocodazole / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D010675:Pheromones / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D012190:Retroviridae / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D014780:Viruses / Q000235:genetics / Q000302:isolation & purification
D004251:DNA Transposable Elements; D005656:Fungal Proteins; D010455:Peptides; D010675:Pheromones; D000072235:Mating Factor; D015739:Nocodazole