Project description:Eco1 is the acetyltransferase that establishes sister-chromatid cohesion during DNA replication. Budding yeast with an eco1 mutation that genocopies Roberts syndrome displaysreduced ribosomal DNA (rDNA) transcription and a transcriptional signature of starvation. Weshow that deleting FOB1, a gene encoding a specific replication fork blocking protein for therDNA region, rescues rRNA production and partially rescues transcription genome-wide. This experiment examines the effect of eco1 mutation on replication genome-wide. Furtherstudies show that deletion of FOB1 corrects the genome-wide replication defects, nucleolarstructure, and rDNA segregation in an eco1 mutant. Our study highlights cohesin's central role atthe rDNA for global control of DNA replication and gene expression. DNA content in eco1-W216G mutant and wt yeast is measured in duplicate by sequencing at 0, 20, and 40 minutes following release from G1 arrest.
Project description:Eco1 is the acetyltransferase that establishes sister-chromatid cohesion during DNA replication. Budding yeast with an eco1 mutation that genocopies Roberts syndrome displaysreduced ribosomal DNA (rDNA) transcription and a transcriptional signature of starvation. Weshow that deleting FOB1, a gene encoding a specific replication fork blocking protein for therDNA region, rescues rRNA production and partially rescues transcription genome-wide. This experiment examines the effect of eco1 mutation on replication genome-wide. Furtherstudies show that deletion of FOB1 corrects the genome-wide replication defects, nucleolarstructure, and rDNA segregation in an eco1 mutant. Our study highlights cohesin's central role atthe rDNA for global control of DNA replication and gene expression.
Project description:Eco1 is an acetyltransferase subunit of the cohesin complex and acts during DNA replication to establish cohesion between sister chromatids. However, cohesin has additional functions in gene expression, DNA damage repair, and higher-order organization of chromosomes. The eco1 mutant W216G disrupts acetyltansferase activity, and causes genome-wide transcriptional defects which can be suppressed by deletion of FOB1, a gene also involved in DNA replication. This experiment investigates gene expression differences between the eco1-W216G mutant, and mutants in FOB1, and RAD61 a gene involved in inhibition of cohesion establishment but mutation of which is able to suppress temperature sensitivity of the eco1-W216G mutant. Wt and mutant strains of yeast were grown to mid log phase in liquid culture in triplicate and harvested for comparison on Affymetrix microarrays. The following strains were compared: 1) eco1-W216G, 2) eco1-W216G fob1Δ, 3) eco1-W216G rad61Δ, 4) fob1Δ, 5) rad61Δ, and 6) WT.
Project description:Eco1 is an acetyltransferase subunit of the cohesin complex and acts during DNA replication to establish cohesion between sister chromatids. However, cohesin has additional functions in gene expression, DNA damage repair, and higher-order organization of chromosomes. The eco1 mutant W216G disrupts acetyltansferase activity, and causes genome-wide transcriptional defects which can be suppressed by deletion of FOB1, a gene also involved in DNA replication. This experiment investigates gene expression differences between the eco1-W216G mutant, and mutants in FOB1, and RAD61 a gene involved in inhibition of cohesion establishment but mutation of which is able to suppress temperature sensitivity of the eco1-W216G mutant.
Project description:TrAEL-seq was performed on hydroxyurea-blocked and then released yeast cells to track replication fork stalling and replication fork restart, in wild-type and replisome mutant strains.
Project description:We investigated the genome-wide distribution of Okazaki fragments in the commonly used laboratory Saccharomyces cerevisiae strain S288C to study the DNA replication model adopted by the budding yeast. The method based upon lambda exonuclease digestion for purification of RNA-primed replication intermediates was first improved to be suitable for the purification of Okazaki fragments. Then, we used this improved method to purify Okazaki fragments from S288C yeast cells, followed by Illumina sequencing. We found that the expected asymmetric distribution of Okazaki fragments around confirmed replication origins, which was derived from the semi-discontinuous DNA replication model, was not observed on S. cerevisiae chromosomes. Even around two highly efficient replication origins, ARS522 and ARS416, the ratios of Okazaki fragments on both strands were inconsistent with the semi-discontinuous DNA replication model. Our study supported the discontinuous DNA replication model. Besides, we also observed that Okazaki fragments were overpresented in the transcribed regions in S. cerevisiae mitochondrial genome, which indicated the interplay between transcription and DNA replication.