Identification of Saccharomyces cerevisiae Genes Whose Deletion Causes Synthetic Effects in Cells with Reduced Levels of the Nuclear Pif1 DNA Helicase.
The multifunctional Saccharomyces cerevisiae Pif1 DNA helicase affects the maintenance of telomeric, ribosomal, and mitochondrial DNAs, suppresses DNA damage at G-quadruplex motifs, influences the processing of Okazaki fragments, and promotes breakage induced replication. All of these functions require the ATPase/helicase activity of the protein. Owing to Pif1's critical role in the maintenance of mitochondrial DNA, pif1Δ strains quickly generate respiratory deficient cells and hence grow very slowly. This slow growth makes it difficult to carry out genome-wide synthetic genetic analysis in this background. Here, we used a partial loss of function allele of PIF1, pif1-m2, which is mitochondrial proficient but has reduced abundance of nuclear Pif1. Although pif1-m2 is not a null allele, pif1-m2 cells exhibit defects in telomere maintenance, reduced suppression of damage at G-quadruplex motifs and defects in breakage induced replication. We performed a synthetic screen to identify nonessential genes with a synthetic sick or lethal relationship in cells with low abundance of nuclear Pif1. This study identified eleven genes that were synthetic lethal (APM1, ARG80, CDH1, GCR1, GTO3, PRK1, RAD10, SKT5, SOP4, UMP1, and YCK1) and three genes that were synthetic sick (DEF1, YIP4, and HOM3) with pif1-m2.
Department of Molecular Biology, Princeton University, New Jersey 08544.
Jennifer L
JL
Stundon
Department of Molecular Biology, Princeton University, New Jersey 08544 vzakian@princeton.edu.
Virginia A
VA
Zakian
D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication; D004843:Epistasis, Genetic; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005804:Genes, Lethal; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
D029701:Saccharomyces cerevisiae Proteins; C085463:PIF1 protein, S cerevisiae; D004265:DNA Helicases
Pif1; S. cerevisiae; helicase; synthetic lethality; yeast