A5076569206- Cellular Mechanics and Interactions
- Force Microscopy Techniques and Applications
- Advanced Fluorescence Microscopy Techniques
- Cardiomyopathy and Myosin Studies
- Microtubule and mitosis dynamics
- 3D Printing in Biomedical Research
- Micro and Nano Robotics
- Adhesion, Friction, and Surface Interactions
- Microfluidic and Bio-sensing Technologies
- Cell Image Analysis Techniques
- Muscle Physiology and Disorders
- RNA Research and Splicing
- Polymer Surface Interaction Studies
- Cardiac Valve Diseases and Treatments
- Sperm and Testicular Function
- Protein Structure and Dynamics
- Cardiac Imaging and Diagnostics
- Fungal and yeast genetics research
- Biocrusts and Microbial Ecology
- Vascular Procedures and Complications
- Genetics, Aging, and Longevity in Model Organisms
- Coronary Interventions and Diagnostics
- Signaling Pathways in Disease
- Trypanosoma species research and implications
- Innovative Microfluidic and Catalytic Techniques Innovation
Centre National de la Recherche Scientifique
2015-2025
Institut Jacques Monod
2016-2025
Université Paris Cité
2016-2025
Institut de Biologie Intégrative de la Cellule
2016-2018
Institut de Biologie Structurale
2018
Hôpital Privé Jacques Cartier
2018
Délégation Paris 5
2017
Hôpital Cochin
2017
Laboratoire d'Enzymologie et Biochimie Structurales
2011-2015
Cytoskeleton (United States)
2011
The contractile actin cortex is a thin layer of actin, myosin, and actin-binding proteins that subtends the membrane animal cells. main determinant cell shape plays fundamental role in division [1Stewart M.P. Helenius J. Toyoda Y. Ramanathan S.P. Muller D.J. Hyman A.A. Hydrostatic pressure actomyosin drive mitotic rounding.Nature. 2011; 469: 226-230Crossref PubMed Scopus (446) Google Scholar, 2Kunda P. Pelling A.E. Liu T. Baum B. Moesin controls cortical rigidity, rounding, spindle...
Actin-depolymerizing factor (ADF)/cofilins contribute to cytoskeletal dynamics by promoting rapid actin filament disassembly. In the classical view, ADF/cofilin sever filaments, and capping proteins block barbed ends whereas pointed depolymerize, at a rate that is still debated. Here, monitoring activity of three mammalian isoforms on individual skeletal muscle cytoplasmic we directly quantify reactions underpinning severing depolymerization from both ends. We find that, in absence monomeric...
Abstract Regulation of the assembly and turnover branched actin filament networks nucleated by Arp2/3 complex is essential during many cellular processes, including cell migration membrane trafficking. Cortactin important for branch stabilization, but mechanism which this occurs unclear. Given this, we determined structure vertebrate cortactin-stabilized branches using cryogenic electron microscopy. We find that cortactin interacts with new daughter at site, rather than initial mother...
The hydrolysis of ATP associated with actin and profilin-actin polymerization is pivotal in cell motility. It at the origin treadmilling filaments controls their dynamics mechanical properties, as well interactions regulatory proteins. slow release inorganic phosphate (Pi) that follows rapid cleavage gamma linked to an increase rate filament disassembly. mechanism Pi has remained elusive for over 20 years. Here, we developed a microfluidic setup accurately monitor depolymerization individual...
AimsWhether or not beta-blocker therapy should be stopped during acutely decompensated heart failure (ADHF) is unsure.
Abstract Filopodia, dynamic membrane protrusions driven by polymerization of an actin filament core, can adhere to the extracellular matrix and experience both external cell-generated pulling forces. The role such forces in filopodia adhesion is however insufficiently understood. Here, we study induced overexpression myosin X, typical for cancer cells. lifetime positively correlates with presence IIA filaments at bases. Application tips through attached fibronectin-coated laser-trapped beads...
The ability of cells to generate forces through actin filament turnover was an early adaptation in evolution. While much is known about how filaments grow, mechanisms their disassembly are incompletely understood. best-characterized factors the cofilin family proteins, which increase cytoskeletal dynamics by severing filaments. However, mechanism severed recycled back monomeric form has remained enigmatic. We report that cyclase-associated-protein (CAP) works synergy with accelerate...
Significance Actin filaments assemble into ordered networks able to exert forces and shape cells. In response, are exposed mechanical stress which can potentially modulate their interactions with regulatory proteins. We developed in vitro tools manipulate single study the impact of mechanics on activity actin depolymerizing factor (ADF)/cofilin, central player disassembly. While tension has almost no effect, curvature enhances severing by ADF/cofilin. also discovered a mechanism that boosts...
CD9 tetraspanin is the only egg membrane protein known to be essential for fertilization. To investigate its role, we have measured, on a unique acrosome reacted sperm brought in contact with an egg, adhesion probability and strength sensitivity of single molecule attachment. Probing binding events at different locations wild-type described modes interaction. Here, show that more gamete occur Cd9 null eggs but strongest interaction mode disappears. We propose sperm–egg fusion direct...
Abstract Proteins targeting actin filament barbed ends play a pivotal role in motile processes. While formins enhance assembly, capping protein (CP) blocks polymerization. On their own, they both bind with high affinity and very slow dissociation. Their barbed-end binding is thought to be mutually exclusive. CP has recently been shown present filopodia controls morphology dynamics. Here we explore how may functionally coregulate assembly. We show, using kinetic analysis of individual...
An in vitro study reveals how the three actin binding proteins profilin, formin 2, and Spire functionally cooperate by a ping-pong mechanism to regulate assembly during reproductive cell division.
Abstract Activation of the Arp2/3 complex by VCA‐motif‐bearing actin nucleation‐promoting factors results in formation “daughter” filaments branching off sides pre‐existing “mother” filaments. Alternatively, when stimulated SPIN90, directly nucleates “linear” Uncovering similarities and differences between these two mechanisms is fundamental to understanding how cytoskeleton dynamics are regulated. Here, analysis individual reveals that, unexpectedly, VCA motifs WASP, N‐WASP, WASH...
Branched actin filaments are found in many key cellular structures. Branches nucleated by the Arp2/3 complex activated nucleation-promoting factor (NPF) proteins and bound to side of preexisting “mother” filaments. Over time, branches dissociate from their mother filament, leading network reorganization turnover, but this mechanism is less understood. Here, using microfluidics purified proteins, we examined dissociation individual under controlled biochemical mechanical conditions. We...
Actin depolymerizing factor (ADF)/cofilin is the main protein family promoting disassembly of actin filaments, which essential for numerous cellular functions. ADF/cofilin proteins disassemble filaments through different reactions, as they bind to their sides, sever them, and promote depolymerization resulting ADF/cofilin-saturated filaments. Moreover, efficiency known be very sensitive pH. thus illustrates two challenges in biochemistry: separating regulatory actions a single characterizing...
Formins are major regulators of actin networks. They enhance filament dynamics by remaining processively bound to barbed ends. How biochemical and mechanical factors affect formin processivity open questions. Monitoring individual filaments in a microfluidic flow, we report that formins mDia1 mDia2 dissociate faster under higher ionic strength when concentration is increased. Profilin, known increase the elongation rate formin-associated filaments, surprisingly decreases dissociation rate,...
The functional importance of the methylation histidine 73 (H73) in actin remains unclear. Focusing on cytoplasmic β-actin, present all mammalian cells, we use molecular dynamics simulations with a polarizable force field and adaptive sampling to examine effects H73 methylation. Our results show that enhances nucleotide binding cleft opening, alters allosteric pathways connecting subdomains 2 4 (SD2 SD4) G-actin, affects backdoor openings inorganic phosphate release F-actin, as validated by...