Roles of the 2 microns gene products in stable maintenance of the 2 microns plasmid of Saccharomyces cerevisiae.
We have examined the replication and segregation of the Saccharomyces cerevisiae 2 microns circle. The amplification of the plasmid at low copy numbers requires site-specific recombination between the 2 microns inverted repeat sequences catalyzed by the plasmid-encoded FLP gene. No other 2 microns gene products are required. The overexpression of FLP in a strain carrying endogenous 2 microns leads to uncontrolled plasmid replication, longer cell cycles, and cell death. Two different assays show that the level of Flp activity decreases with increasing 2 microns copy number. This regulation requires the products of the REP1 and REP2 genes. These gene products also act together to ensure that 2 microns molecules are randomly segregated between mother and daughter cells at cell division.
Reynolds
A E
AE
Department of Molecular Biology, Massachusetts General Hospital, Boston 02114.
Murray
A W
AW
Szostak
J W
JW
D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics*; D005656:Fungal Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D005796:Genes; D005800:Genes, Fungal; D008938:Mitosis; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000235:genetics; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D004271:DNA, Fungal; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins