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Domaines de Recherche: - Physique/Physique/Biophysique
- Physique/Matière Condensée/Mécanique statistique
- Physique/Matière Condensée/Systèmes désordonnés et réseaux de neurones
- Science non linéaire/Automates cellulaires et gaz sur réseau
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Dernieres productions scientifiques :
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Modeling Cytoskeletal Traffic: An Interplay between Passive Diffusion and Active Transport 
Auteur(s): NERI I., KERN N., PARMEGGIANI A.
(Article) Publié:
Physical Review Letters, vol. 110 p.098102 (2013)
Ref HAL: hal-00805162_v1
DOI: 10.1103/PhysRevLett.110.098102
Résumé: We introduce the totally asymmetric simple exclusion process with Langmuir kinetics on a network as a microscopic model for active motor protein transport on the cytoskeleton, immersed in the diffusive cytoplasm.We discuss how the interplay between active transport along a network and infinite diffusion in a bulk reservoir leads to a heterogeneous matter distribution on various scales: we find three regimes for steady state transport, corresponding to the scale of the network, of individual segments, or local to sites. At low exchange rates strong density heterogeneities develop between different segments in the network. In this regime one has to consider the topological complexity of the whole network to describe transport. In contrast, at moderate exchange rates the transport through the network decouples, and the physics is determined by single segments and the local topology. At last, for very high exchange rates the homogeneous Langmuir process dominates the stationary state. We introduce effective rate diagrams for the network to identify these different regimes. Based on this method we develop an intuitive but generic picture of how the stationary state of excluded volume processes on complex networks can be understood in terms of the single-segment phase diagram.
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Towards modelling motor protein driven cytoskeltal transport
Auteur(s): KERN N. , Parmeggiani A., RAGUIN A., NERI I.
Conference: Mechanisms driving the organization of intra-cellular organelles (Zaragoza, ES, 2012-06-18)
Résumé: One important role which the cytoskeleton plays in cells is to provide a network of filaments along which molecular motors can procede. This provides an essential mechanism by which a cell can establish transport of cargos over distances of the order of the cell size. The details of how such motors achieve procession along the biofilaments constituting the cytoskeleton are very complex indeed, but much of their behaviour (including collective aspects of the transport) can be described in terms of well-established models, such as the Totally Asymmetric Transport Process (TASEP) or similar. These are well-studied on single filaments. Recent work has allowed us to establish a framework to transpose this understanding to an overall network of interconnected filaments, mimicking the cytoskeleton. We discuss how new aspects of heterogeneity arise on the network scale, and we aOne important role which the cytoskeleton plays in cells is to provide a network of filaments along which molecular motors can procede. This provides an essential mechanism by which a cell can establish transport of cargos over distances of the order of the cell size. The details of how such motors achieve procession along the biofilaments constituting the cytoskeleton are very complex indeed, but much of their behaviour (including collective aspects of the transport) can be described in terms of well-established models, such as the Totally Asymmetric Transport Process (TASEP) or similar. These are well-studied on single filaments. Recent work has allowed us to establish a framework to transpose this understanding to an overall network of interconnected filaments, mimicking the cytoskeleton. We discuss how new aspects of heterogeneity arise on the network scale, and we argue that they are generic to many types of transport on networks. We also present very recent ideas for incorporating more complex features aimed at applying the approach to cytoskeletal transport in particular.
rgue that they are generic to many types of transport on networks. We also present very recent ideas for incorporating more complex features aimed at applying the approach to cytoskeletal transport in particular.
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Active Transport on Networks
Auteur(s): NERI I.
(Séminaires)
Journées plénières du GDR Physique de la Cellule au Tissu (Lille, FR), 2011-10-13 |
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Izaak.Neri
lcvn.univ-montp2.fr 
0467144677
Bureau: 237, Bât: 13 - Site : Campus Triolet
