Spatiotemporal control of microtubule nucleation and assembly using magnetic nanoparticles


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.

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Figure 1: Magnetic nanoparticles bioconjugated to signalling proteins controlling microtubule assembly.
Figure 2: Signalling proteins conjugated to magnetic nanoparticles promote microtubule assembly.
Figure 3: Magnetic control of microtubule nucleation and assembly.
Figure 4: Magnetically induced microtubule arrays are polarized, organized by dynein motors and can be manipulated by magnetic forces.
Figure 5: Microtubule assembly triggered by guanine exchange factor RCC1.


  1. 1

    Kholodenko, B. N., Hancock, J. F. & Kolch, W. Signalling ballet in space and time. Nature Rev. Mol. Cell. Biol. 11, 414–426 (2010).

    CAS  Article  Google Scholar 

  2. 2

    Kinkhabwala, A. & Bastiaens, P. I. Spatial aspects of intracellular information processing. Curr. Opin. Genet. Dev. 20, 31–40 (2010).

    CAS  Article  Google Scholar 

  3. 3

    Karsenti, E. Self-organization in cell biology: a brief history. Nature Rev. Mol. Cell. Biol. 9, 255–262 (2008).

    CAS  Article  Google Scholar 

  4. 4

    Chiang, K. P. & Muir, T. W. Systems- and molecular-level elucidation of signaling processes through chemistry. Sci. Signal 1, pe45 (2008).

    Article  Google Scholar 

  5. 5

    Ellis-Davies, G. C. Caged compounds: photorelease technology for control of cellular chemistry and physiology. Nature Methods 4, 619–628 (2007).

    CAS  Article  Google Scholar 

  6. 6

    Grunwald, C. et al. In situ assembly of macromolecular complexes triggered by light. Proc. Natl Acad. Sci. USA 107, 6146–6151 (2010).

    CAS  Article  Google Scholar 

  7. 7

    Toettcher, J. E., Voigt, C. A., Weiner, O. D. & Lim, W. A. The promise of optogenetics in cell biology: interrogating molecular circuits in space and time. Nature Methods 8, 35–38 (2011).

    CAS  Article  Google Scholar 

  8. 8

    Wu, Y. I. et al. A genetically encoded photoactivatable Rac controls the motility of living cells. Nature 461, 104–108 (2009).

    CAS  Article  Google Scholar 

  9. 9

    Levskaya, A., Weiner, O. D., Lim, W. A. & Voigt, C. A. Spatiotemporal control of cell signalling using a light-switchable protein interaction. Nature 461, 997–1001 (2009).

    CAS  Article  Google Scholar 

  10. 10

    Lim, W. A. Designing customized cell signalling circuits. Nature Rev. Mol. Cell. Biol. 11, 393–403 (2010).

    CAS  Article  Google Scholar 

  11. 11

    Doktycz, M. J. & Simpson, M. L. Nano-enabled synthetic biology. Mol. Syst. Biol. 3, 1–10 (2007).

    Article  Google Scholar 

  12. 12

    Wilner, O. I. et al. Enzyme cascades activated on topologically programmed DNA scaffolds. Nature Nanotech. 4, 249–254 (2009).

    CAS  Article  Google Scholar 

  13. 13

    Kiel, C., Yus, E. & Serrano, L. Engineering signal transduction pathways. Cell 140, 33–47 (2010).

    CAS  Article  Google Scholar 

  14. 14

    Chen, C. S. Biotechnology: remote control of living cells. Nature Nanotech. 3, 13–14 (2008).

    CAS  Article  Google Scholar 

  15. 15

    Mannix, R. J. et al. Nanomagnetic actuation of receptor-mediated signal transduction. Nature Nanotech. 3, 36–40 (2008).

    CAS  Article  Google Scholar 

  16. 16

    Lee, J-H. et al. Artificial control of cell signaling and growth by magnetic nanoparticles. Angew. Chem. Int. Ed. 49, 5698–5702 (2010).

    CAS  Article  Google Scholar 

  17. 17

    Steketee, M. B. et al. Nanoparticle-mediated signaling endosome localization regulates growth cone motility and neurite growth. Proc. Natl Acad. Sci. USA 108, 19042–19047 (2011).

    CAS  Article  Google Scholar 

  18. 18

    Desai, A., Murray, A., Mitchison, T. J. & Walczak, C. E. The use of Xenopus egg extracts to study mitotic spindle assembly and function in vitro. Methods Cell Biol. 61, 385–412 (1999).

    CAS  Article  Google Scholar 

  19. 19

    Hannak, E. & Heald, R. Investigating mitotic spindle assembly and function in vitro using Xenopus laevis egg extracts. Nature Protoc. 1, 2305–2314 (2006).

    CAS  Article  Google Scholar 

  20. 20

    Vetter, I. R. & Wittinghofer, A. The guanine nucleotide-binding switch in three dimensions. Science 294, 1299–1304 (2001).

    CAS  Article  Google Scholar 

  21. 21

    Vartak, N. & Bastiaens, P. Spatial cycles in G-protein crowd control. EMBO J. 29, 2689–2699 (2010).

    CAS  Article  Google Scholar 

  22. 22

    Kalab, P. & Heald, R. The RanGTP gradient—a GPS for the mitotic spindle. J. Cell Sci. 121, 1577–1586 (2008).

    CAS  Article  Google Scholar 

  23. 23

    Carazo-Salas, R. E. et al. Generation of GTP-bound Ran by RCC1 is required for chromatin-induced mitotic spindle formation. Nature 400, 178–181 (1999).

    CAS  Article  Google Scholar 

  24. 24

    Karsenti, E. & Vernos, I. The mitotic spindle: a self-made machine. Science 294, 543–547 (2001).

    CAS  Article  Google Scholar 

  25. 25

    Wittmann, T., Hyman, A. & Desai, A. The spindle: a dynamic assembly of microtubules and motors. Nature Cell Biol. 3, E28–E34 (2001).

    CAS  Article  Google Scholar 

  26. 26

    Clarke, P. R. & Zhang, C. Spatial and temporal coordination of mitosis by Ran GTPase. Nature Rev. Mol. Cell Biol. 9, 464–477 (2008).

    CAS  Article  Google Scholar 

  27. 27

    Caudron, M., Bunt, G., Bastiaens, P. & Karsenti, E. Spatial coordination of spindle assembly by chromosome-mediated signaling gradients. Science 309, 1373–1376 (2005).

    CAS  Article  Google Scholar 

  28. 28

    Toyoshima, Y., Kakuda, H., Fujita, K. A., Uda, S. & Kuroda, S. Sensitivity control through attenuation of signal transfer efficiency by negative regulation of cellular signalling. Nature Commun. 3, 743 (2012).

    Article  Google Scholar 

  29. 29

    Kaláb, P., Pralle, A., Isacoff, E. Y., Heald, R. & Weis, K. Analysis of a RanGTP-regulated gradient in mitotic somatic cells. Nature 440, 697–701 (2006).

    Article  Google Scholar 

  30. 30

    Jimenez, A. M. et al. Towards high throughput production of artificial egg oocytes using microfluidics. Lab. Chip 11, 429–434 (2011).

    CAS  Article  Google Scholar 

  31. 31

    Pinot, M. et al. Effects of confinement on the self-organization of microtubules and motors. Curr. Biol. 19, 954–960 (2009).

    CAS  Article  Google Scholar 

  32. 32

    Li, R. & Gundersen, G. G. Beyond polymer polarity: how the cytoskeleton builds a polarized cell. Nature Rev. Mol. Cell Biol. 9, 860–873 (2008).

    CAS  Article  Google Scholar 

  33. 33

    Halpin, D., Kalab, P., Wang, J., Weis, K. & Heald, R. Mitotic spindle assembly around RCC1-coated beads in Xenopus egg extracts. PLoS Biol. 9, e1001225 (2011).

    CAS  Article  Google Scholar 

  34. 34

    Gaetz, J., Gueroui, Z., Libchaber, A. & Kapoor, T. M. Examining how the spatial organization of chromatin signals influences metaphase spindle assembly. Nature Cell Biol. 8, 924–932 (2006).

    CAS  Article  Google Scholar 

  35. 35

    Bastiaens, P., Caudron, M., Niethammer, P. & Karsenti, E. Gradients in the self-organization of the mitotic spindle. Trends Cell Biol. 16, 125–134 (2006).

    CAS  Article  Google Scholar 

  36. 36

    Athale, C. A. et al. Regulation of microtubule dynamics by reaction cascades around chromosomes. Science 322, 1243–1247 (2008).

    CAS  Article  Google Scholar 

  37. 37

    Soh, S., Byrska, M., Kandere-Grzybowska, K. & Grzybowski, B. A. Reaction-diffusion systems in intracellular molecular transport and control. Angew. Chem. Int. Ed. 49, 4170–4198 (2010).

    CAS  Article  Google Scholar 

  38. 38

    Bryant, D. M. & Mostov, K. E. From cells to organs: building polarized tissue. Nature Rev. Mol. Cell Biol. 9, 887–901 (2008).

    CAS  Article  Google Scholar 

  39. 39

    Good, M. C., Zalatan, J. G. & Lim, W. A. Scaffold proteins: hubs for controlling the flow of cellular information. Science 332, 680–686 (2011).

    CAS  Article  Google Scholar 

  40. 40

    Bashor, C. J., Horwitz, A. A., Peisajovich, S. G. & Lim, W. A. Rewiring cells: synthetic biology as a tool to interrogate the organizational principles of living systems. Annu. Rev. Biophys. 39, 515–537 (2010).

    CAS  Article  Google Scholar 

  41. 41

    Grunberg, R. & Serrano, L. Strategies for protein synthetic biology. Nucleic Acids Res. 38, 2663–2675 (2010).

    Article  Google Scholar 

  42. 42

    Osterfield, M., Kirschner, M. W. & Flanagan, J. G. Graded positional information: interpretation for both fate and guidance. Cell 113, 425–428 (2003).

    CAS  Article  Google Scholar 

  43. 43

    Izaurralde, E., Kutay, U., von Kobbe, C., Mattaj, I. W. & Görlich, D. The asymmetric distribution of the constituents of the Ran system is essential for transport into and out of the nucleus. EMBO J. 16, 6535–6547 (1997).

    CAS  Article  Google Scholar 

  44. 44

    Kutay, U., Izaurralde, E., Bischoff, F. R., Mattaj, I. W. & Görlich, D. Dominant-negative mutants of importin-beta block multiple pathways of import and export through the nuclear pore complex. EMBO J. 16, 1153–1163 (1997).

    CAS  Article  Google Scholar 

  45. 45

    Pinot, M. et al. Confinement induces actin flow in a meiotic cytoplasm. Proc. Natl Acad. Sci. USA 109, 11705–11710 (2012).

    CAS  Article  Google Scholar 

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The authors thank I. Mattaj and B. Koch for the RanQ69L and RCC1 expression plasmids, K. Weis for the Rango expression plasmid and N. Morin for the Ran(T24N) expression plasmid. The authors also thank F. Guyot, J.M. Guignier and L. Largeau for electron microscopy observations. Thanks also go to F. Grasset, A. Gautier, L. Jullien, T. Le Saux, A. Libchaber, N. Nerambourg, C. Tribet, J. Wu and the members of the Biophysical Chemistry Center of ENS for fruitful discussions. This work was supported by the CNRS, the Association pour la Recherche sur le Cancer (SFI20101201426), the Ligue Nationale Contre le Cancer (LNCC, 2009) and Ville de Paris ‘Emergence’ (to Z.G.), the Agence Nationale de la Recherche (ANR, ANR-08-PNANO-050 to R.LB., V.M., C.G. and Z.G.), FRM, Triangle de la Physique (to E.M.) and ATIP CNRS (to R.LB.).

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C.H. and Z.G. conceived and designed the experiments. C.H., S.L. and Z.G. performed the experiments. E.M. and C.G. performed the simulations. All authors analysed the data. C.G., R.L.B. and V.M. contributed materials/analysis tools. C.H. and Z.G. wrote the manuscript and all authors commented on it.

Corresponding author

Correspondence to Zoher Gueroui.

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Hoffmann, C., Mazari, E., Lallet, S. et al. Spatiotemporal control of microtubule nucleation and assembly using magnetic nanoparticles. Nature Nanotech 8, 199–205 (2013).

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