A5050683716- Cancer-related Molecular Pathways
- DNA Repair Mechanisms
- Genomics and Chromatin Dynamics
- Fungal and yeast genetics research
- Microtubule and mitosis dynamics
- Single-cell and spatial transcriptomics
- RNA Research and Splicing
- Carcinogens and Genotoxicity Assessment
- Bioinformatics and Genomic Networks
- Chromosomal and Genetic Variations
- Cancer Genomics and Diagnostics
- Cell Image Analysis Techniques
- CRISPR and Genetic Engineering
- Photosynthetic Processes and Mechanisms
- Molecular Biology Techniques and Applications
- RNA modifications and cancer
- DNA and Nucleic Acid Chemistry
- Cancer Research and Treatments
- Gut microbiota and health
- Gene Regulatory Network Analysis
- Advanced Fluorescence Microscopy Techniques
- Epigenetics and DNA Methylation
- Mitochondrial Function and Pathology
- interferon and immune responses
- Plant Genetic and Mutation Studies
Harvard University
2017-2024
Broad Institute
2017-2021
Boston VA Research Institute
2021
Center for Systems Biology
2017-2020
Brandeis University
2012-2019
Fun30 is a Swi2/Snf2 homolog in budding yeast that has been shown to remodel chromatin both vitro and vivo. We report plays key role homologous recombination, by facilitating 5'-to-3' resection of double-strand break (DSB) ends, apparently exonuclease digestion nucleosome-bound DNA adjacent the DSB. recruited an HO endonuclease-induced DSB acts Exo1-dependent Sgs1-dependent pathways. Deletion FUN30 slows rate from 4 kb/h about 1.2 kb/h. also found reduced damage-induced phosphorylation...
The Mre11-Rad50-Xrs2 nuclease complex, together with Sae2, initiates the 5'-to-3' resection of Double-Strand DNA Breaks (DSBs). Extended 3' single stranded filaments can be exposed from a DSB through redundant activities Exo1 and Dna2 Sgs1 helicase. In absence Mre11 binding to is prolonged, two ends cannot kept tethered, not efficiently repaired. Here we show that deletion yeast 53BP1-ortholog RAD9 reduces DSB, leading Rad52 recruitment efficient end-tethering, an Sgs1-dependent mechanism....
In response to chromosomal double-strand breaks (DSBs), eukaryotic cells activate the DNA damage checkpoint, which is orchestrated by PI3 kinase-like protein kinases ATR and ATM (Mec1 Tel1 in budding yeast). Following DSB formation, Mec1 phosphorylate histone H2A on serine 129 (known as γ-H2AX). We used caffeine inhibit checkpoint after induction. show that prolonged phosphorylation of H2A-S129 does not require continuous activity. Unexpectedly, treatment impaired homologous recombination...
Cellular responses to stimuli can evolve over time, resulting in distinct early and late phases response a single signal. DNA damage induces complex that is largely orchestrated by the transcription factor p53, whose dynamics influence whether damaged cell will arrest repair or initiate death. How p53 cellular outcomes presence of continuous remains unknown. Here, we have found subset cells switches from oscillating sustained several days after undergoing damage. The switch results cycle...
We have used two different live-cell fluorescent protein markers to monitor the formation and localization of double-strand breaks (DSBs) in budding yeast. Using GFP derivatives Rad51 recombination or Ddc2 checkpoint protein, we find that cells with three site-specific DSBs, on chromosomes, usually display 2 3 foci may coalesce dissociate. This motion is independent Rad52 microtubules. Rad51-GFP, by itself, unable repair DSBs homologous mitotic cells, but able form allow when heterozygous a...
To allow for sufficient time to repair DNA double-stranded breaks (DSBs), eukaryotic cells activate the damage checkpoint. In budding yeast, Rad53 (mammalian Chk2) phosphorylation parallels persistence of unrepaired DSB and is extinguished when complete in a process termed recovery or adapt A strain containing slowly repaired does not require histone chaperone Asf1 resume cell cycle progression after repair. When second, rapidly repairable added this strain, becomes required recovery....
Abstract Background The tumor suppressor p53 is a major regulator of the DNA damage response and has been suggested to selectively bind activate cell-type specific gene expression programs. However recent studies meta-analyses genomic data propose largely uniform, condition independent binding thus question selective dependent function p53. Results To systematically assess specificity p53, we measured its association with in 12 wild-type cancer cell lines, from range epithelial linages,...
Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation a Rad51 recombinase filament that forms single-stranded DNA (ssDNA) created at DSB ends. This facilitates search for donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells increasing non-productive interactions between random regions genome. Here we show prevents conversion yeast, independently its...
Abstract Non-genetic mechanisms have recently emerged as important drivers of therapy failure in cancer (Salgia and Kulkarni, 2018), where some cells can enter a reversible drug-tolerant persister state response to treatment (Vallette et al., 2019). While most persisters, like their bacterial counterparts, remain arrested the presence drug, rare subset persisters re-enter cell cycle under constitutive drug (Sharma 2010). Little is known about non-genetic that enable maintain proliferative...
(Cell Reports 32, 107995-1–107995-12, e1–e4; August 4, 2020) In the originally published version of this paper, Figure 4 (original) panel C is missing two inhibitory arrow heads, one from PIDDosome to Mdm2 and p53. (corrected) has been corrected now appears here with paper online. The authors regret error.Figure 4The Caspase-2-PIDDosome Contributes Switch in p53 Dynamics (original)View Large Image ViewerDownload Hi-res image Download (PPT) A Marks Cells That Escape DSB-Induced Cell Cycle...
Transcriptional inactivation of the budding yeast centromere has been a widely used tool in studies chromosome segregation and aneuploidy. In haploid cells when an essential contains single conditionally inactivated (GAL-CEN), cell growth rate is slowed fidelity reduced; but colony formation nearly 100%. Pedigree analysis revealed that only 30% time both mother daughter inherit GAL-CEN chromosome. The reduced capacity further compromised upon reduction pericentric cohesin (mcm21∆), as...
Genetically identical cells can respond heterogeneously to cancer therapy, with a subpopulation of often entering temporarily arrested treatment-tolerant state before repopulating the tumor. To investigate how heterogeneity in cell cycle arrest protein p21 arises, we imaged dynamics transcription and expression along those p53, its transcriptional regulator, single using live fluorescence microscopy. Surprisingly, found that rate depends on change p53 rather than absolute level. Through...
In eukaryotes, double‐stranded break repair (DSB) takes place in the context of chromatin. Saccharomyces cerevisiae mating type ( MAT ) switching provides an opportunity to investigate nucleosome dynamics around a well‐characterized DSB. is initiated by synchronous induction DSB HO endonuclease at locus following which ends are resected and Rad51 recombinase loaded on 3‐ended single strand. facilitates strand invasion with homologous donor sequence, required for initiation new DNA synthesis...
A single double-strand break (DSB) triggers the ATR/ATM (Mec1/Tel1)-dependent DNA damage response in budding yeast. These kinases phosophorylate not only histone H2A (γ-H2AX) but also C-terminal threonine of H2B (γ-H2B), both which contribute to checkpoint responses and repair DSB. Despite being phosphorylated by same kinases, γ-H2AX kinetics are much more rapid than that γ-H2B, when is mutated prevent its phosphorylation, γ-H2B adopt seen for γ-H2AX. Both modifications removed PP4...
In response to DNA double stranded break H2AX undergoes rapid phosphorylation by the checkpoint PI3 Kinases ATM and ATR. This modification, termed γ‐H2AX, persists as long damage is present. We used caffeine, a known kinase inhibitor, ask if modification requires continuous activation of ATR in Saccharomyces cerevisiae . find that inhibition Mec1 Tel1, yeast's homologues respectively, does not lead loss γ‐H2AX. Also we show, for first time, upon caffeine treatment Rad53 Rad9 are rapidly...
Abstract We have used two different live-cell fluorescent protein markers to monitor the formation and localization of double-strand breaks (DSBs) in budding yeast. Using GFP derivatives Rad51 recombination or Ddc2 checkpoint protein, we find that cells with three site-specific DSBs, on chromosomes, usually display 2 3 foci coalesce dissociate. Rad51-GFP, by itself, is unable repair DSBs homologous mitotic cells, but able form allow when heterozygous a wild type protein. The kinetics...