A5058213120- DNA Repair Mechanisms
- DNA and Nucleic Acid Chemistry
- CRISPR and Genetic Engineering
- Genomics and Chromatin Dynamics
- PARP inhibition in cancer therapy
- Nanopore and Nanochannel Transport Studies
- Advanced biosensing and bioanalysis techniques
- Bacterial Genetics and Biotechnology
- RNA Interference and Gene Delivery
- Microtubule and mitosis dynamics
- Microfluidic and Capillary Electrophoresis Applications
- RNA modifications and cancer
- RNA Research and Splicing
- Cancer therapeutics and mechanisms
- RNA and protein synthesis mechanisms
- Advanced Fluorescence Microscopy Techniques
- interferon and immune responses
- Carcinogens and Genotoxicity Assessment
- Microfluidic and Bio-sensing Technologies
- Cancer Diagnosis and Treatment
- Medical Imaging Techniques and Applications
- Bacteriophages and microbial interactions
- Breast Lesions and Carcinomas
- Metastasis and carcinoma case studies
- Radiopharmaceutical Chemistry and Applications
Aix-Marseille Université
2016-2025
Centre de Recherche en Cancérologie de Marseille
2015-2024
Institut Pprime
2021-2024
Inserm
2015-2024
Cancer Research Center
2012-2024
Centre National de la Recherche Scientifique
2015-2024
Institut Paoli-Calmettes
2013-2024
University of Florence
2023
Université Paris Cité
2021
Délégation Paris 5
2021
DNA double-strand break (DSB) repair by nonhomologous end joining (NHEJ) requires the assembly of several proteins on ends. Although biochemical studies have elucidated aspects NHEJ reaction mechanism, much less is known about in living cells, mainly because inability to visualize at damage. Here we provide evidence that a pulsed near IR laser can produce DSBs without any visible alterations nucleus, and show accumulate irradiated areas. The levels Ku accumulation diminished time, showing...
Single-molecule manipulation studies have revealed that double-stranded DNA undergoes a structural transition when subjected to tension. At forces depend on the attachment geometry of (65 pN or 110 pN), it elongates approximately 1.7-fold and its elastic properties change dramatically. The nature this overstretched has been under debate. In one model, cooperatively unwinds, while base pairing remains intact. competing hydrogen bonds between pairs break two single strands are formed,...
Cytoplasmic linker protein (CLIP)-170, CLIP-115, and the dynactin subunit p150Glued are structurally related proteins, which associate specifically with ends of growing microtubules (MTs). Here, we show that down-regulation CLIP-170 by RNA interference results in a strongly reduced accumulation at MT tips. The NH2 terminus binds directly to COOH through its second metal-binding motif. LIS1, dynein-associating protein, compete for interaction terminus, suggesting LIS1 can act release from We...
Mechanical stress plays a key role in many genomic processes, such as DNA replication and transcription. The ability to predict the response of double-stranded (ds) tension is cornerstone understanding mechanics. It widely appreciated that torsionally relaxed dsDNA exhibits structural transition at forces ∼65 pN, known overstretching, whereby contour length molecule increases by ∼70%. Despite extensive investigation, changes occurring during overstretching are still generating considerable...
DNA double-strand breaks pose a significant threat to cell survival and must be repaired. In higher eukaryotes, such damage is repaired efficiently by non-homologous end joining (NHEJ). Within this pathway, XRCC4 XLF fulfill key roles required for joining. Using DNA-binding -bridging assays, combined with direct visualization, we present evidence how XRCC4–XLF complexes robustly bridge molecules. This unanticipated, Ligase IV-independent bridging activity suggests an early role complex...
Nonhomologous end-joining represents the major pathway used by human cells to repair DNA double-strand breaks. It relies on XRCC4/DNA ligase IV complex reseal strands. Here we report high-resolution crystal structure of XRCC4 bound carboxy-terminal tandem BRCT repeat IV. The differs from homologous Saccharomyces cerevisiae and reveals an extensive binding interface formed a helix-loop-helix within inter-BRCT linker region, as well significant interactions involving second domain, which...
RAD51 promotes homologous recombination repair (HR) of double-strand breaks and acts during DNA replication to facilitate fork reversal protect nascent strands from nuclease digestion. Several additional HR proteins regulate protection by promoting filament formation. Here, we show that RADX modulates stalled antagonizing RAD51. Consequently, silencing restores in cells deficient for BRCA1, BRCA2, FANCA, FANCD2, or BOD1L. Inactivating prevents both MRE11- DNA2-dependent degradation....
Abstract Guanine-rich DNA sequences occur throughout the human genome and can transiently form G-quadruplex (G4) structures that may obstruct replication, leading to genomic instability. Here, we apply multi-color single-molecule localization microscopy (SMLM) coupled with robust data-mining algorithms quantitatively visualize replication fork (RF)-coupled formation spatial-association of endogenous G4s. Using this data, investigate effects G4s on replisome dynamics organization. We show a...
Abstract Homologous recombination (HR) factors were recently implicated in DNA replication fork remodeling and protection. While maintaining genome stability, HR-mediated promotes cancer chemoresistance, by as-yet elusive mechanisms. Five HR cofactors – the RAD51 paralogs RAD51B, RAD51C, RAD51D, XRCC2 XRCC3 emerged as crucial tumor suppressors. Albeit extensively characterized repair, their role has not been addressed systematically. Here, we identify all while screening for modulators of...
Alternative lengthening of telomeres (ALT) is a homology-directed repair (HDR) mechanism telomere elongation that controls proliferation in subsets aggressive cancer. Recent studies have revealed repeat-containing RNA (TERRA) promotes ALT-associated HDR (ALT-HDR). Here, we report RAD51AP1, crucial ALT factor, interacts with TERRA and utilizes it to generate D- R-loop HR intermediates. We also show RAD51AP1 binds might stabilize TERRA-containing R-loops as depletion reduces formation at DNA...
The human DNA repair protein RAD51 is the crucial component of helical nucleoprotein filaments that drive homologous recombination. molecular mechanistic details how this structure facilitates requisite strand rearrangements are not known but must involve dynamic interactions between and DNA. Here, we report real-time kinetics filament assembly disassembly on individual molecules both single- double-stranded DNA, as measured using magnetic tweezers. relative rates nucleation extension such...
Nonhomologous end joining is the primary deoxyribonucleic acid (DNA) double-strand break repair pathway in multicellular eukaryotes. To initiate repair, Ku binds DNA ends and recruits DNA-dependent protein kinase (DNA-PK) catalytic subunit (DNA-PKcs) forming holoenzyme. Early synapsis associated with autophosphorylation. The XRCC4 (X4)–DNA Ligase IV (LIG4) complex (X4LIG4) executes final ligation promoted by Cernunnos (Cer)–X4-like factor (XLF). In this paper, using a cell-free system that...
Significance The mechanism of RAD51-recombinase filament formation is visualized and quantified with single-molecule resolution using a combination dual optical tweezers, fluorescence microscopy, microfluidics. With this method, short-lived transient intermediates formed during nascent RAD51 assembly were observed directly. It that nuclei consisting variable number monomers bind from solution to DNA, an interaction time increases nucleus size. Nuclei remain bound DNA long enough can grow by...
Stretching DNA in nanochannels is a useful tool for direct, visual studies of genomic at the single molecule level. To facilitate study interaction linear with proteins nanochannels, we have implemented highly effective passivation scheme based on lipid bilayers. We demonstrate virtually complete long-term nanochannel surfaces to range relevant reagents, including streptavidin-coated quantum dots, RecA proteins, and RecA–DNA complexes. show that performance bilayer significantly better than...