A5006041544- DNA Repair Mechanisms
- Genomics and Chromatin Dynamics
- Metal-Catalyzed Oxygenation Mechanisms
- Mitochondrial Function and Pathology
- RNA modifications and cancer
- DNA and Nucleic Acid Chemistry
- Fungal and yeast genetics research
- Cancer Genomics and Diagnostics
- RNA and protein synthesis mechanisms
- Epigenetics and DNA Methylation
- Metal complexes synthesis and properties
- Microtubule and mitosis dynamics
- Metabolism and Genetic Disorders
- RNA Research and Splicing
- CRISPR and Genetic Engineering
- Carcinogens and Genotoxicity Assessment
- Biochemical and Molecular Research
- Bacterial Genetics and Biotechnology
- Genetic factors in colorectal cancer
- Cancer-related Molecular Pathways
- Telomeres, Telomerase, and Senescence
- Molecular Biology Techniques and Applications
- HIV/AIDS drug development and treatment
- Cancer therapeutics and mechanisms
- Science, Research, and Medicine
Umeå University
2016-2025
National Institutes of Health
2010
University at Albany, State University of New York
2009
Albany State University
2009
Cold Spring Harbor Laboratory
2003-2007
Heidelberg University
2001
Swiss Tropical and Public Health Institute
2001
Stockholm University
2000
La Salle University
1999
Measurements of nucleoside triphosphate levels in Saccharomyces cerevisiae reveal that the four rNTPs are 36- to 190-fold molar excess over their corresponding dNTPs. During DNA synthesis vitro using physiological concentrations, yeast polymerase ε , which is implicated leading strand replication, incorporates one rNMP for every 1,250 dNMPs. Pol δ and α, conduct lagging incorporate 5,000 or 625 dNMPs, respectively. Discrimination against incorporation varies widely, some cases by more than...
DNA must be synthesized for purposes of genome duplication and repair. While the former is a highly accurate process, short-patch synthesis associated with repair damage often error-prone. Break-induced replication (BIR) unique cellular process that mimics normal in its processivity, rate, capacity to duplicate hundreds kilobases, but initiated at double-strand breaks (DSBs) rather than origins. Here we employed series frameshift reporters measure mutagenesis BIR Saccharomyces cerevisiae. We...
How parental histone (H3-H4)2 tetramers, the primary carriers of epigenetic modifications, are transferred onto leading and lagging strands DNA replication forks for inheritance remains elusive. Here we show that tetramers assembled into nucleosomes both strands, with a slight preference strands. The lagging-strand increases markedly in budding yeast cells lacking Dpb3 Dpb4, two subunits strand polymerase, Pol ε, owing to impairment transfer Dpb3-Dpb4 binds H3-H4 vitro participates...
The mechanisms by which imbalanced dNTPs induce mutations have been well characterized within a test tube, but not in vivo. We examined dNTP imbalances genome instability strains of Saccharomyces cerevisiae with different amino acid substitutions Rnr1, the large subunit ribonucleotide reductase. These that correlate elevated CAN1 mutation rates, both substitution and insertion–deletion rates increasing 10- to 300-fold. locations strain dTTP dCTP are completely from those dATP dGTP. Thus,...
A balanced supply of deoxyribonucleoside triphosphates (dNTPs) is one the key prerequisites for faithful genome duplication. Both overall concentration and balance among individual dNTPs (dATP, dTTP, dGTP, dCTP) are tightly regulated, primarily by enzyme ribonucleotide reductase (RNR). We asked whether dNTP pool imbalances interfere with cell cycle progression detected S-phase checkpoint, a surveillance mechanism activated in response to DNA damage or replication blocks. By introducing...
Significance The three major DNA replication fidelity determinants are nucleotide selectivity, proofreading, and mismatch repair. Defects in the two latter now firmly associated with cancer. Nucleotide selectivity is affected by changes absolute or relative concentrations of dNTPs. Here, we show that hemizygous SAMHD1 +/− mouse embryos have increased dNTP pools compared wild-type controls heterozygous mutations inactivate frequently found colon cancers. We infer such cancer cells and,...
Ribonucleotide reductase (RNR) plays a central role in the formation and control of optimal levels deoxyribonucleoside triphosphates, which are required for DNA replication repair processes. Mammalian RNRs composed two nonidentical subunits, proteins R1 R2. The limiting R2 protein overall RNR activity during mammalian cell cycle, being undetectable G1 phase increasing S phase. We show that proliferating cells, transcription gene, once activated beginning phase, reaches its maximum 6–7 h...
Ribonucleotide reductase (RNR) catalyzes the reduction of ribonucleotides to deoxyribonucleotides; this step is rate-limiting in DNA precursor synthesis. A number regulatory mechanisms ensure optimal deoxyribonucleotide pools, which are essential for cell viability. The best studied transcriptional regulation RNR genes during cycle and response damage, allosteric ribonucleotide by nucleoside triphosphates. Recently, another mode has been hypothesized yeast. novel protein, Sml1, was shown...
In eukaryotic cells the concentration of dNTP is highest in S phase and lowest G1 controlled by ribonucleotide reductase (RNR). RNR activity eliminated all eukaryotes a variety mechanisms: transcriptional regulation, small inhibitory proteins, protein degradation. After activation upon commitment to phase, dATP feedback inhibition ensures that does not exceed certain maximal level. It apparent why limitation necessary phase. principle, should be sufficient couple production utilization. We...
The absolute and relative concentrations of the four dNTPs are key determinants DNA replication fidelity, yet consequences altered dNTP pools on fidelity have not previously been investigated a genome-wide scale. Here, we use deep sequencing to determine types, rates locations uncorrected errors that accumulate in nuclear genome mismatch repair-deficient diploid yeast strain with elevated dCTP dTTP concentrations. These imbalanced promote specific sequence motifs suggesting increased...
The Saccharomyces cerevisiae Dun1 protein kinase is a downstream target of the conserved Mec1-Rad53 checkpoint pathway. regulates dNTP pools during an unperturbed cell cycle and after DNA damage by modulating activity ribonucleotide reductase (RNR) multiple mechanisms, including phosphorylation RNR inhibitors Sml1 Dif1. also activates DNA-damage-inducible genes inhibiting Crt1 transcriptional repressor. Among repressed are three out four genes: RNR2, RNR3, RNR4. fourth gene, RNR1,...
// Stefan J. Barfeld 1 , Ladan Fazli 2 Margareta Persson 3 Lisette Marjavaara 4 Alfonso Urbanucci Kirsi M. Kaukoniemi 5 Paul S. Rennie Yvonne Ceder Andrei Chabes Tapio Visakorpi Ian G. Mills 1, 6, 7 Prostate Research Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, The Vancouver Centre, British Columbia, Canada Department Laboratory Medicine, Division Clinical Chemistry, Lund University, Malmö, Sweden Medical Biochemistry and Biophysics,...
Abstract Alterations in the exonuclease domain of DNA polymerase ε (Polε) cause ultramutated tumors. Severe mutator effects most common variant, Polε-P286R, modeled yeast suggested that its pathogenicity involves yet unknown mechanisms beyond simple proofreading deficiency. We show that, despite producing a catastrophic amount replication errors vivo, Polε-P286R analog retains partial activity and is more accurate than exonuclease-dead Polε. The major consequence arginine substitution...
Ribonucleotide reductases catalyze the formation of deoxyribonucleotides by reduction corresponding ribonucleotides. Eukaryotic ribonucleotide are α2β2 tetramers; each larger, α subunits possesses binding sites for substrate and allosteric effectors, smaller, β contains a binuclear iron complex. The complex interacts with specific tyrosine residue to form tyrosyl free radical which is essential activity. Previous work has identified two genes in yeast Saccharomyces cerevisiae, RNR1 RNR3,...