A5037193422- DNA Repair Mechanisms
- Carcinogens and Genotoxicity Assessment
- DNA and Nucleic Acid Chemistry
- Plant Genetic and Mutation Studies
- Genomics and Chromatin Dynamics
- Mitochondrial Function and Pathology
- CRISPR and Genetic Engineering
- Microtubule and mitosis dynamics
- Cancer-related Molecular Pathways
- RNA and protein synthesis mechanisms
- Porphyrin Metabolism and Disorders
- Genetic Neurodegenerative Diseases
- RNA modifications and cancer
- Telomeres, Telomerase, and Senescence
- Genetics and Neurodevelopmental Disorders
- Bacterial Genetics and Biotechnology
- PARP inhibition in cancer therapy
- BRCA gene mutations in cancer
- Advanced biosensing and bioanalysis techniques
- Viral gastroenteritis research and epidemiology
- Genetic factors in colorectal cancer
- Photosynthetic Processes and Mechanisms
- RNA Interference and Gene Delivery
- Genetics, Aging, and Longevity in Model Organisms
- Viral Infections and Immunology Research
National Institute on Aging
2015-2025
National Institutes of Health
2009-2023
Istituto Superiore di Sanità
2013
National Cancer Institute
2013
Institute on Aging
2013
Laboratory of Molecular Genetics
2013
University of Baltimore
2013
United States Department of Health and Human Services
2004
Modulation of DNA repair proteins by small molecules has attracted great interest. An in vitro helicase activity screen was used to identify that modulate unwinding Werner syndrome (WRN), mutated the premature aging disorder syndrome. A molecule from National Cancer Institute Diversity Set designated NSC 19630 [1-(propoxymethyl)-maleimide] identified inhibited WRN but did not affect other helicases [Bloom (BLM), Fanconi anemia group J (FANCJ), RECQ1, RecQ, UvrD, or DnaB). Exposure human...
G-quadruplex (G4) DNA, an alternate structure formed by Hoogsteen hydrogen bonds between guanines in G-rich sequences, threatens genomic stability perturbing normal DNA transactions including replication, repair, and transcription. A variety of G4 topologies (intra- intermolecular) can form vitro, but the molecular architecture cellular factors influencing landscape vivo are not clear. Helicases that unwind structured molecules emerging as important class G4-resolving enzymes. The...
Human Werner Syndrome is characterized by early onset of aging, elevated chromosomal instability, and a high incidence cancer. protein (WRN) member the <i>rec</i>Q gene family, but unlike other members it contains unique 3′→5′ exonuclease activity. We have reported previously that human Ku heterodimer interacts physically with WRN functionally stimulates Because DNA-PKcs, catalytic subunit DNA-dependent kinase (DNA-PK), form complex at DNA ends, we now explored possibility functional...
RecQ helicases play an important role in preserving genomic integrity, and their cellular roles DNA repair, recombination, replication have been of considerable interest. Of the five human identified, three are associated with genetic disorders characterized by elevated incidence cancer or premature aging: Werner syndrome, Bloom Rothmund-Thomson syndrome. Although biochemical properties protein interactions WRN BLM defective syndrome respectively, extensively investigated, less information...
We have investigated the DNA substrate specificity of BACH1 (BRCA1-associated C-terminal helicase). The importance various structural elements for efficient unwinding by purified recombinant helicase was examined. results indicated that preferentially binds and unwinds a forked duplex compared with flanked only one single-stranded (ssDNA) tail. In support its preference, sequestration studies revealed can be trapped molecules. requires minimal 5 ' ssDNA tail 15 nucleotides conventional...
The single-stranded DNA-binding protein replication A (RPA) interacts with several human RecQ DNA helicases that have important roles in maintaining genomic stability; however, the mechanism for RPA stimulation of unwinding is not well understood. To map regions Werner syndrome helicase (WRN) interact RPA, yeast two-hybrid studies, WRN affinity pull-down experiments and enzyme-linked immunosorbent assays purified recombinant fragments were performed. results indicated has two binding sites,...
Mutations in the FANCJ helicase predispose individuals to breast cancer and are genetically linked Fanconi anemia (FA) complementation group J. FA is a chromosomal instability disorder characterized by multiple congenital anomalies, progressive bone marrow failure, high risk. has been proposed function downstream of FANCD2 monoubiquitination, critical event pathway. Evidence supports role for homologous recombination pathway double strand break repair. In an effort understand molecular...
Werner syndrome is genetically linked to mutations in WRN that encodes a DNA helicase-nuclease believed operate at stalled replication forks. Using newly identified small-molecule inhibitor of helicase (NSC 617145), we investigated the role interstrand cross-link (ICL) response cells derived from patients with Fanconi anemia, hereditary disorder characterized by bone marrow failure and cancer. In FA-D2(-/-) cells, NSC 617145 acted synergistically very low concentrations mitomycin C inhibit...
Despite being the first homolog of bacterial RecQ helicase to be identified in humans, function RECQL1 remains poorly characterized. Furthermore, unlike other members human RECQ family helicases, mutations have not been associated with a genetic disease. Here, we identify 2 families genome instability disorder that named RECON (RECql ONe) syndrome, caused by biallelic RECQL gene. The affected individuals had short stature, progeroid facial features, hypoplastic nose, xeroderma, and skin...
Replication of the 30-kilobase genome SARS-CoV-2, responsible for COVID-19, is a key step in coronavirus life cycle that requires set virally encoded nonstructural proteins such as highly conserved Nsp13 helicase. However, features contribute to catalytic properties are not well established. Here, we biochemically characterized purified recombinant SARS-CoV-2 helicase protein, focusing on its functions, nucleic acid substrate specificity, nucleotide/metal cofactor requirements, and...
Werner Syndrome is a premature aging disorder characterized by genomic instability, elevated recombination, and replication defects. It has been hypothesized that defective processing of certain fork structures WRN may contribute to instability. Fluorescence resonance energy transfer (FRET) analyses show Flap Endonuclease-1 (FEN-1) form complex in vivo colocalizes foci associated with arrested forks. effectively stimulates FEN-1 cleavage branch-migrating double-flap are the physiological...
Werner syndrome is a hereditary premature aging disorder characterized by genome instability. The product of the gene defective in WS, WRN, helicase/exonuclease that presumably functions DNA metabolism. To understand structures WRN acts upon vivo, we examined its substrate preferences for unwinding. unwound 3′-single-stranded (ss)DNA-tailed duplex with streptavidin bound to end 3′-ssDNA tail, suggesting does not require free unwind duplex; however, was completely blocked tail 6 nucleotides...
Werner syndrome (WS) is characterized by the early onset of symptoms premature aging, cancer, and genomic instability. The molecular basis defects not understood but presumably relates to DNA helicase exonuclease activities protein encoded <i>WRN</i> gene that mutated in disease. attenuation p53-mediated apoptosis WS cells reported physical interaction between WRN tumor suppressor p53 suggest functionally interact a pathway necessary for normal cellular response. In this study, we have...
Bloom's syndrome (BS) is a rare autosomal recessive genetic disorder associated with genomic instability and an elevated risk of cancer. Cellular features BS include accumulation abnormal replication intermediates increased sister chromatid exchange. Although it has been suggested that the underlying defect responsible for hyper-recombination in cells temporal delay maturation DNA intermediates, precise role gene product, BLM, metabolism remains elusive. We report here novel interaction BLM...
Mutations in the gene encoding iron–sulfur-containing DNA helicase DDX11 (ChlR1) were recently identified as a cause of new recessive cohesinopathy, Warsaw breakage syndrome (WABS), single patient with severe microcephaly, pre- and postnatal growth retardation, abnormal skin pigmentation. Here, using homozygosity mapping Lebanese consanguineous family followed by exome sequencing, we novel homozygous mutation (c.788G>A [p.R263Q]) three affected siblings intellectual disability many...
Our recently published work suggests that DNA helicases such as the Werner syndrome helicase (WRN) represent a novel class of proteins to target for anticancer therapy. Specifically, pharmacological inhibition WRN activity in human cells defective Fanconi anemia (FA) pathway interstrand cross-link (ICL) repair are sensitized cross-linking agent and chemotherapy drug mitomycin C (MMC) by inhibitor NSC 617145. (1) The mechanistic basis synergistic interaction between 617145 MMC is discussed...
FANCJ mutations are linked to Fanconi anemia (FA) and increase breast cancer risk. encodes a DNA helicase implicated in homologous recombination (HR) repair of double-strand breaks (DSBs) interstrand cross-links (ICLs), but its mechanism action is not well understood. Here we show with live-cell imaging that recruitment laser-induced DSBs psoralen-induced ICLs dependent on nuclease-active MRE11. interacts directly MRE11 inhibits exonuclease activity specific manner, suggesting regulates the...
Regulation of end-processing is critical for accurate repair and to switch between homologous recombination (HR) non-homologous end joining (NHEJ). End resection a two-stage process but very little known about regulation the long-range resection, especially in humans. WRN participates one two alternative pathways mediated by DNA2 or EXO1. Here we demonstrate that phosphorylation CDK1 essential perform DNA2-dependent at replication-related DSBs, promoting HR, replication recovery chromosome...