scholarly journals Pol32, a Subunit of Saccharomyces cerevisiae DNA Polymerase δ, Suppresses Genomic Deletions and Is Involved in the Mutagenic Bypass Pathway

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1409-1422 ◽  
Author(s):  
Meng-Er Huang ◽  
Anne-Gaëlle Rio ◽  
Marie-Dominique Galibert ◽  
Francis Galibert
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Polymerase ◽  
Genome Stability ◽  
Double Mutant ◽  
Direct Repeats ◽  
Genomic Deletions ◽  
Mutator Effect ◽  
A Subunit ◽  
Mutation Spectra ◽  
Forward Mutation

Abstract The Pol32 subunit of S. cerevisiae DNA polymerase (Pol) δ plays an important role in replication and mutagenesis. Here, by measuring the CAN1 forward mutation rate, we found that either POL32 or REV3 (which encodes the Pol ζ catalytic subunit) inactivation produces overlapping antimutator effects against rad mutators belonging to three epistasis groups. In contrast, the msh2Δ pol32Δ double mutant exhibits a synergistic mutator phenotype. Canr mutation spectrum analysis of pol32Δ strains revealed a substantial increase in the frequency of deletions and duplications (primarily deletions) of sequences flanked by short direct repeats, which appears to be RAD52 and RAD10 independent. To better understand the pol32Δ and rev3Δ antimutator effects in rad backgrounds and the pol32Δ mutator effect in a msh2Δ background, we determined Canr mutation spectra for rad5Δ, rad5Δ pol32Δ, rad5Δ rev3Δ, msh2Δ, msh2Δ pol32Δ, and msh2Δ rev3Δ strains. Both rad5Δ pol32Δ and rad5Δ rev3Δ mutants exhibit a reduction in frameshifts and base substitutions, attributable to antimutator effects conferred by the pol32Δ and rev3Δ mutations. In contrast, an increase in these two types of alterations is attributable to a synergistic mutator effect between the pol32Δ and msh2Δ mutations. Taken together, these observations indicate that Pol32 is important in ensuring genome stability and in mutagenesis.

scholarly journals Replication slippage between distant short repeats in Saccharomyces cerevisiae depends on the direction of replication and the RAD50 and RAD52 genes.

1995 ◽  
Vol 15 (10) ◽  
pp. 5607-5617 ◽  
Author(s):  
H T Tran ◽  
N P Degtyareva ◽  
N N Koloteva ◽  
A Sugino ◽  
H Masumoto ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genome Stability ◽  
Genome Instability ◽  
Temperature Sensitive ◽  
Direct Repeats ◽  
Dna Polymerase Delta ◽  
Dna Double Strand Breaks ◽  
Yeast Saccharomyces Cerevisiae ◽  
Replication Slippage ◽  
Random Sequences

Small direct repeats, which are frequent in all genomes, are a potential source of genome instability. To study the occurrence and genetic control of repeat-associated deletions, we developed a system in the yeast Saccharomyces cerevisiae that was based on small direct repeats separated by either random sequences or inverted repeats. Deletions were examined in the LYS2 gene, using a set of 31- to 156-bp inserts that included inserts with no apparent potential for secondary structure as well as two quasipalindromes. All inserts were flanked by 6- to 9-bp direct repeats of LYS2 sequence, providing an opportunity for Lys+ reversion via precise excision. Reversions could arise by extended deletions involving either direct repeats or random sequences and by -1-or +2-bp frameshift mutations. The deletion breakpoints were always associated with short (3- to 9-bp) perfect or imperfect direct repeats. Compared with the POL+ strain, deletions between small direct repeats were increased as much as 100-fold, and the spectrum was changed in a temperature-sensitive DNA polymerase delta pol3-t mutant, suggesting a role for replication. The type of deletion depended on orientation relative to the origin of replication. On the basis of these results, we propose (i) that extended deletions between small repeats arise by replication slippage and (ii) that the deletions occur primarily in either the leading or lagging strand. The RAD50 and RAD52 genes, which are required for the recombinational repair of many kinds of DNA double-strand breaks, appeared to be required also for the production of up to 90% of the deletions arising between separated repeats in the pol3-t mutant, suggesting a newly identified role for these genes in genome stability and possibly replication.

scholarly journals Increased Rates of Genomic Deletions Generated by Mutations in the Yeast Gene Encoding DNA Polymerase δ or by Decreases in the Cellular Levels of DNA Polymerase δ

2000 ◽  
Vol 20 (20) ◽  
pp. 7490-7504 ◽  
Author(s):  
Robert J. Kokoska ◽  
Lela Stefanovic ◽  
Jeremy DeMai ◽  
Thomas D. Petes
Keyword(s):  
Dna Polymerase ◽  
Genome Stability ◽  
Gene Encoding ◽  
Mutator Phenotype ◽  
Genomic Deletions ◽  
Dna Polymerase Δ ◽  
Mutation Avoidance ◽  
Increased Sensitivity

ABSTRACT In Saccharomyces cerevisiae, POL3 encodes the catalytic subunit of DNA polymerase δ. While yeastPOL3 mutant strains that lack the proofreading exonuclease activity of the polymerase have a strong mutator phenotype, little is known regarding the role of other Pol3p domains in mutation avoidance. We identified a number of pol3 mutations in regions outside of the exonuclease domain that have a mutator phenotype, substantially elevating the frequency of deletions. These deletions appear to reflect an increased frequency of DNA polymerase slippage. In addition, we demonstrate that reduction in the level of wild-type DNA polymerase results in a similar mutator phenotype. Lowered levels of DNA polymerase also result in increased sensitivity to the DNA-damaging agent methyl methane sulfonate. We conclude that both the quantity and the quality of DNA polymerase δ is important in ensuring genome stability.

scholarly journals DNA polymerases δ and λ cooperate in repairing double-strand breaks by microhomology-mediated end-joining in Saccharomyces cerevisiae

2015 ◽  
Vol 112 (50) ◽  
pp. E6907-E6916 ◽  
Author(s):  
Damon Meyer ◽  
Becky Xu Hua Fu ◽  
Wolf-Dietrich Heyer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Polymerase ◽  
Genome Stability ◽  
Double Strand Breaks ◽  
Dna Polymerase Delta ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Repair Efficiency ◽  
Repair Pathways

Maintenance of genome stability is carried out by a suite of DNA repair pathways that ensure the repair of damaged DNA and faithful replication of the genome. Of particular importance are the repair pathways, which respond to DNA double-strand breaks (DSBs), and how the efficiency of repair is influenced by sequence homology. In this study, we developed a genetic assay in diploid Saccharomyces cerevisiae cells to analyze DSBs requiring microhomologies for repair, known as microhomology-mediated end-joining (MMEJ). MMEJ repair efficiency increased concomitant with microhomology length and decreased upon introduction of mismatches. The central proteins in homologous recombination (HR), Rad52 and Rad51, suppressed MMEJ in this system, suggesting a competition between HR and MMEJ for the repair of a DSB. Importantly, we found that DNA polymerase delta (Pol δ) is critical for MMEJ, independent of microhomology length and base-pairing continuity. MMEJ recombinants showed evidence that Pol δ proofreading function is active during MMEJ-mediated DSB repair. Furthermore, mutations in Pol δ and DNA polymerase 4 (Pol λ), the DNA polymerase previously implicated in MMEJ, cause a synergistic decrease in MMEJ repair. Pol λ showed faster kinetics associating with MMEJ substrates following DSB induction than Pol δ. The association of Pol δ depended on RAD1, which encodes the flap endonuclease needed to cleave MMEJ intermediates before DNA synthesis. Moreover, Pol δ recruitment was diminished in cells lacking Pol λ. These data suggest cooperative involvement of both polymerases in MMEJ.

scholarly journals Base Composition of Mononucleotide Runs Affects DNA Polymerase Slippage and Removal of Frameshift Intermediates by Mismatch Repair in Saccharomyces cerevisiae

2002 ◽  
Vol 22 (24) ◽  
pp. 8756-8762 ◽  
Author(s):  
Hana Gragg ◽  
Brian D. Harfe ◽  
Sue Jinks-Robertson
Keyword(s):  
Mismatch Repair ◽  
Dna Polymerase ◽  
Genome Stability ◽  
The Status ◽  
Nucleotide Insertion ◽  
Mismatch Recognition ◽  
Mutation Assay ◽  
Simple Repeats ◽  
Forward Mutation ◽  
Polymerase Slippage

ABSTRACT The postreplicative mismatch repair (MMR) system is important for removing mutational intermediates that are generated during DNA replication, especially those that arise as a result of DNA polymerase slippage in simple repeats. Here, we use a forward mutation assay to systematically examine the accumulation of frameshift mutations within mononucleotide runs of variable composition in wild-type and MMR-defective yeast strains. These studies demonstrate that (i) DNA polymerase slippage occurs more often in 10-cytosine/10-guanine (10C/10G) runs than in 10-adenine/10-thymine (10A/10T) runs, (ii) the MMR system removes frameshift intermediates in 10A/10T runs more efficiently than in 10C/10G runs, (iii) the MMR system removes −1 frameshift intermediates more efficiently than +1 intermediates in all 10-nucleotide runs, and (iv) the repair specificities of the Msh2p-Msh3p and Msh2p-Msh6p mismatch recognition complexes with respect to 1-nucleotide insertion/deletion loops vary dramatically as a function of run composition. These observations are relevant to issues of genome stability, with both the rates and types of mutations that accumulate in mononucleotide runs being influenced by the primary sequence of the run as well as by the status of the MMR system.

scholarly journals Saccharomyces cerevisiae DNA Polymerase ε and Polymerase σ Interact Physically and Functionally, Suggesting a Role for Polymerase ε in Sister Chromatid Cohesion

2003 ◽  
Vol 23 (8) ◽  
pp. 2733-2748 ◽  
Author(s):  
Shaune Edwards ◽  
Caroline M. Li ◽  
Daniel L. Levy ◽  
Jessica Brown ◽  
Peter M. Snow ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Polymerase ◽  
Sister Chromatid ◽  
Large Subunit ◽  
Polymerase Activity ◽  
Sister Chromatid Cohesion ◽  
Nucleotidyl Transferase ◽  
C Terminus ◽  
Chromatid Cohesion ◽  
A Subunit

ABSTRACT The large subunit of Saccharomyces cerevisiae DNA polymerase ε, Pol2, comprises two essential functions. The N terminus has essential DNA polymerase activity. The C terminus is also essential, but its function is unknown. We report here that the C-terminal domain of Pol2 interacts with polymerase σ (Pol σ), a recently identified, essential nuclear nucleotidyl transferase encoded by two redundant genes, TRF4 and TRF5. This interaction is functional, since Pol σ stimulates the polymerase activity of the Pol ε holoenzyme significantly. Since Trf4 is required for sister chromatid cohesion as well as for completion of S phase and repair, the interaction suggested that Pol ε, like Pol σ, might form a link between the replication apparatus and sister chromatid cohesion and/or repair machinery. We present evidence that pol2 mutants are defective in sister chromatid cohesion. In addition, Pol2 interacts with SMC1, a subunit of the cohesin complex, and with ECO1/CTF7, required for establishing sister chromatid cohesion; and pol2 mutations act synergistically with smc1 and scc1. We also show that trf5Δ mutants, like trf4Δ mutants, are defective in DNA repair and sister chromatid cohesion.

scholarly journals A novel variant of DNA polymerase ζ, Rev3ΔC, highlights differential regulation of Pol32 as a subunit of polymerase δ versus ζ in Saccharomyces cerevisiae

DNA Repair ◽  
2014 ◽  
Vol 24 ◽  
pp. 138-149 ◽  
Author(s):  
Hollie M. Siebler ◽  
Artem G. Lada ◽  
Andrey G. Baranovskiy ◽  
Tahir H. Tahirov ◽  
Youri I. Pavlov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Polymerase ◽  
Differential Regulation ◽  
Novel Variant ◽  
A Subunit

scholarly journals A targeted next generation sequencing approach to develop robust, genotype-specific mutation profiles and uncover novel variants in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Natalie A. Lamb ◽  
Jonathan Bard ◽  
Michael J. Buck ◽  
Jennifer A. Surtees
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genome Stability ◽  
Underlying Mechanism ◽  
Position Effects ◽  
Replication Fidelity ◽  
Specific Mutation ◽  
Targeted Next Generation Sequencing ◽  
A Cell ◽  
Mutation Spectra ◽  
The Impact

ABSTRACTDistinct mutation signatures arise from environmental exposures and/or from defects in metabolic pathways that promote genome stability. The presence of a particular mutation signature in a cell or a tumor can therefore predict the underlying mechanism of mutagenesis, which, in practice, may be clinically important. These insults to the genome often alter dNTP pools, which itself impacts replication fidelity. Therefore, the impact of altered dNTP pools should be considered when making mechanistic predictions based on mutation signatures. We developed a targeted deep-sequencing approach on the CAN1 gene in Saccharomyces cerevisiae to define information-rich mutational profiles associated with distinct rnr1 backgrounds that alter replication fidelity by elevating dNTP levels.. The mutation spectra of rnr1Y285F and rnr1Y285A alleles were characterized previously; our analysis was consistent with this prior work but the sequencing depth achieved in our study allowed a significantly more robust and nuanced computational analysis of the variants observed, generating profiles that integrated information about mutation spectra, position effects, and sequence context. This approach revealed novel, genotype-specific mutation profiles in the presence of even modest changes in dNTP pools. Furthermore, we identified broader sequence contexts and specific nucleotide motifs that influenced variant profiles in different rnr1 backgrounds, which allowed us to make specific mechanistic predictions about the impact of altered dNTP pools on replication fidelity.

scholarly journals GC content elevates mutation and recombination rates in the yeast Saccharomyces cerevisiae

2018 ◽  
Vol 115 (30) ◽  
pp. E7109-E7118 ◽  
Author(s):  
Denis A. Kiktev ◽  
Ziwei Sheng ◽  
Kirill S. Lobachev ◽  
Thomas D. Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Polymerase ◽  
Base Composition ◽  
Genome Stability ◽  
Gc Content ◽  
Substantial Effect ◽  
Recombination Rates ◽  
Yeast Saccharomyces Cerevisiae ◽  
Basic Parameters ◽  
Elevated Rate

The chromosomes of many eukaryotes have regions of high GC content interspersed with regions of low GC content. In the yeast Saccharomyces cerevisiae, high-GC regions are often associated with high levels of meiotic recombination. In this study, we constructed URA3 genes that differ substantially in their base composition [URA3-AT (31% GC), URA3-WT (43% GC), and URA3-GC (63% GC)] but encode proteins with the same amino acid sequence. The strain with URA3-GC had an approximately sevenfold elevated rate of ura3 mutations compared with the strains with URA3-WT or URA3-AT. About half of these mutations were single-base substitutions and were dependent on the error-prone DNA polymerase ζ. About 30% were deletions or duplications between short (5–10 base) direct repeats resulting from DNA polymerase slippage. The URA3-GC gene also had elevated rates of meiotic and mitotic recombination relative to the URA3-AT or URA3-WT genes. Thus, base composition has a substantial effect on the basic parameters of genome stability and evolution.

Sign in / Sign up

Export Citation Format

Share Document