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Looping and Clustering: a statistical physics approach to protein-DNA complexes in bacteria
Auteur(s): Walliser N.-O.
Conference: APS March Meeting 2019 (Boston, US, 2019-03-04)
Texte intégral en Openaccess :
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Résumé: The DNA shows a high degree of spatial and dynamical organization over a broad range of length scales. It interacts with different populations of proteins and can form protein-DNA complexes that underlie various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, an essential component of a widely spread mechanism for DNA segregation in bacteria. Recent studies suggest that DNA-bound ParB proteins interact with each other and condense into large clusters with multiple extruding DNA-loops. In my talk, I present the Looping and Clustering model [1], a simple statistical physics approach to describe how proteins assemble into a protein-DNA cluster with multiple loops. Our analytic model predicts binding profiles of ParB proteins in good agreement with data from high precision ChIP-sequencing – a biochemical technique to analyze the interaction between DNA and proteins at the level of the genome. The Looping and Clustering framework provides a quantitative tool that could be exploited to interpret further experimental results of ParB-like protein complexes and gain some new insights into the organization of DNA.[1] Walter, J.-C., Walliser, N.-O., ... & Broedersz, C. P., New J. Phys. 20, 035002 (2018).
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Modelling Spatio-temporal Dynamic of Ribosome During Translation
Auteur(s): Chevalier C., Walter J.-C., Palmeri J., Parmeggiani A., Geniet F., Dorignac J., Walliser N.-O., Rivals Eric, Paulet Damien, David Alexandre
(Affiches/Poster)
7ème Journées Scientifiques du LabEx NUMEV (Montpellier, FR), 2018-11-27Texte intégral en Openaccess :
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Résumé: Translation of messenger RNA (mRNA) leads to the production of proteins and is the last step of gene expression in cells. The dysregulation of translation can lead to all illnesses linked to the dysregulation of protein production, like cancer and neurodegenerative diseases.About ten years ago, a ribosomal density mapping strategy (Ribo-seq) was developed. The time is therefore ripe to apply theoretical physicsmethods to study translation. We model the movement of ribosomes on mRNA using the Totally Asymmetric Simple Exclusion Process (TASEP) which is an out of equilibrium one dimensional directed transport model. With Monte Carlo simulations and a mean field approach, we propose a way to calculate the speed of ribosomes from experimental data. Moreover, we provide preliminary results concerning the correlation between the speed of ribosomes and the occurrence rate of codons (RSCU).
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Looping and Clustering: a statistical physics approach to protein-DNA complexes in bacteria
Auteur(s): Walter J.-C., Walliser N.-O., David G., Dorignac J., Geniet F., Palmeri J., Parmeggiani A., Wingreen Ned S., Broedersz Chase P.
(Affiches/Poster)
EMBO | EMBL Symposium: Cellular Mechanisms Driven by Liquid Phase Separation (Heidelberg, DE), 2018-05-14
Ref HAL: hal-01939915_v1
Exporter : BibTex | endNote
Résumé: The DNA shows a high degree of spatial and dynamical organization over a broad range of length scales. It interacts with different populations of proteins and can form protein-DNA complexes that underlie various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, an essential component of a widely spread mechanism for DNA segregation in bacteria. Recent studies suggest that DNA-bound ParB proteins interact with each other and condense into large clusters with multiple extruding DNA-loops.In my talk, I present the Looping and Clustering model [1], a simple statistical physics approach to describe how proteins assemble into a protein-DNA cluster with multiple loops. Our analytic model predicts binding profiles of ParB proteins in good agreement with data from high precision ChIP-sequencing – a biochemical technique to analyze the interaction between DNA and proteins at the level of the genome. The Looping and Clustering framework provides a quantitative tool that could be exploited to interpret further experimental results of ParB-like protein complexes and gain some new insights into the organization of DNA.
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Looping and Clustering: a statistical physics approach to protein-DNA complexes in bacteria
Auteur(s): Walliser N.-O.
(Séminaires)
L2C, Université de Montpellier (Montpellier, FR), 2018-02-15 |
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Looping and Clustering: a statistical physics approach to protein-DNA complexes in bacteria
Auteur(s): Walliser N.-O.
Conference: Chromatin Meets South (Montpellier, FR, 2018-06-12)
Ref HAL: hal-01939901_v1
Exporter : BibTex | endNote
Résumé: The DNA shows a high degree of spatial and dynamical organization over a broad range of length scales. It interacts with different populations of proteins and can form protein-DNA complexes that underlie various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, an essential component of a widely spread mechanism for DNA segregation in bacteria. Recent studies suggest that DNA-bound ParB proteins interact with each other and condense into large clusters with multiple extruding DNA-loops. In my talk, I present the Looping and Clustering model, a simple statistical physics approach to describe how proteins assemble into a protein-DNA cluster with multiple loops. Our analytic model predicts binding profiles of ParB proteins in good agreement with data from high precision ChIP-sequencing – a biochemical technique to analyze the interaction between DNA and proteins at the level of the genome. The Looping and Clustering framework provides a quantitative tool that could be exploited to interpret further experimental results of ParB-like protein complexes and gain some new insights into the organization of DNA.
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Looping and Clustering model for the organization of protein-DNA complexes on the bacterial genome
Auteur(s): Walliser N.-O.
Conference: Réunion annuelle du GdR ADN (Millau, FR, 2018-04-09)
Ref HAL: hal-01939895_v1
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Résumé: The bacterial genome is organized by a variety of associated proteins inside a structure called the nucleoid. These proteins can form complexes on DNA that play a central role in various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, which forms an essential component of the segregation machinery in many bacteria. ChIP-Seq experiments show that ParB proteins localize around centromere-like parS sites on the DNA to which ParB binds specifically, and spreads from there over large sections of the chromosome. Recent theoretical and experimental studies suggest that DNA-bound ParB proteins can interact with each other to condense into a coherent 3D complex on the DNA. However, the structural organization of this protein-DNA complex remains unclear, and a predictive quantitative theory for the distribution of ParB proteins on DNA is lacking. Here, we propose the Looping and Clustering (LC) model, which employs a statistical physics approach to describe protein-DNA complexes. The LC model accounts for the extrusion of DNA loops from a cluster of interacting DNA-bound proteins that is organized around a single high-affinity binding site. Conceptually, the structure of the protein-DNA complex is determined by a competition between attractive protein interactions and the configurational and loop entropy of this protein-DNA cluster. Indeed, we show that the protein interaction strength determines the "tightness" of the loopy protein-DNA complex. Thus, our model provides a theoretical framework to quantitatively compute the binding profiles of ParB-like proteins around a cognate parS binding site.
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DNA-loops and the organization of protein-DNA complexes in bacteria
Auteur(s): Walliser N.-O.
Conference: Journées de Physique Statistique 2018 (Paris, FR, 2018-01-25)
Ref HAL: hal-01939889_v1
Exporter : BibTex | endNote
Résumé: The DNA shows a high degree of spatial and dynamical organization over a broad range of length scales. It interacts with different populations of proteins and can form protein-DNA complexes that underlie various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, an essential component of a widely spread mechanism for DNA segregation in bacteria. Recent studies suggest that DNA-bound ParB proteins interact with each other and condense into large clusters with multiple extruding DNA-loops. In my talk, I present the Looping and Clustering model, a simple statistical physics approach to describe how proteins assemble into a protein-DNA cluster with multiple loops. Our analytic model predicts binding profiles of ParB proteins in good agreement with data from high precision ChIP-sequencing – a biochemical technique to analyze the interaction between DNA and proteins at the level of the genome. The Looping and Clustering framework provides a quantitative tool that could be exploited to interpret further experimental results of ParB-like protein complexes and gain some new insights into the organization of DNA.
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