title: Spatiotemporal control of microtubule nucleation and assembly using magnetic nanoparticles.
abstract: Decisions on the fate of cells and their functions are dictated by the spatiotemporal dynamics of molecular signalling networks. However, techniques to examine the dynamics of these intracellular processes remain limited. Here, we show that magnetic nanoparticles conjugated with key regulatory proteins can artificially control, in time and space, the Ran/RCC1 signalling pathway that regulates the cell cytoskeleton. In the presence of a magnetic field, RanGTP proteins conjugated to superparamagnetic nanoparticles can induce microtubule fibres to assemble into asymmetric arrays of polarized fibres in Xenopus laevis egg extracts. The orientation of the fibres is dictated by the direction of the magnetic force. When we locally concentrated nanoparticles conjugated with the upstream guanine nucleotide exchange factor RCC1, the assembly of microtubule fibres could be induced over a greater range of distances than RanGTP particles. The method shows how bioactive nanoparticles can be used to engineer signalling networks and spatial self-organization inside a cell environment.
authors: Département de Chimie, Ecole Normale Supérieure, UMR 8640 CNRS-ENS-UPMC Pasteur, 24, rue Lhomond, 75005 Paris, France.
authors: Céline
authors: C
authors: Hoffmann
authors: Elsa
authors: E
authors: Mazari
authors: Sylvie
authors: S
authors: Lallet
authors: Roland
authors: R
authors: Le Borgne
authors: Valérie
authors: V
authors: Marchi
authors: Charlie
authors: C
authors: Gosse
authors: Zoher
authors: Z
authors: Gueroui
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000302:isolation & purification*; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000737:chemistry; D003599:Cytoskeleton / Q000737:chemistry* / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000302:isolation & purification*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009687:Nuclear Proteins / Q000737:chemistry / Q000302:isolation & purification*; D015398:Signal Transduction; D014982:Xenopus laevis / Q000378:metabolism; D020931:ran GTP-Binding Protein / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D058185:Magnetite Nanoparticles; D009687:Nuclear Proteins; C062521:RCC1 protein, human; D020931:ran GTP-Binding Protein