Letter | Published:

Targeting of the F-actin-binding protein drebrin by the microtubule plus-tip protein EB3 is required for neuritogenesis

Nature Cell Biology volume 10, pages 11811189 (2008) | Download Citation



Interactions between dynamic microtubules and actin filaments (F-actin) underlie a range of cellular processes including cell polarity and motility. In growth cones, dynamic microtubules are continually extending into selected filopodia, aligning alongside the proximal ends of the F-actin bundles. This interaction is essential for neuritogenesis and growth-cone pathfinding. However, the molecular components mediating the interaction between microtubules and filopodial F-actin have yet to be determined. Here we show that drebrin, an F-actin-associated protein, binds directly to the microtubule-binding protein EB3. In growth cones, this interaction occurs specifically when drebrin is located on F-actin in the proximal region of filopodia and when EB3 is located at the tips of microtubules invading filopodia. When this interaction is disrupted, the formation of growth cones and the extension of neurites are impaired. We conclude that drebrin targets EB3 to coordinate F-actin–microtubule interactions that underlie neuritogenesis.

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  1. 1.

    , , & Microtubule reorganization is obligatory for growth cone turning. Proc. Natl Acad. Sci. USA 93, 15221–15226 (1996).

  2. 2.

    , & Focal loss of actin bundles causes microtubule redistribution and growth cone turning. J. Cell Biol. 157, 839–849 (2002).

  3. 3.

    & in Neurochemistry, A Practical Approach (eds Turner, A. J. & Bachelard, H. S.) 1–38 (IRL Press, London, 1997).

  4. 4.

    et al. APC binds to the novel protein EB1. Cancer Res. 55, 2972–2977 (1995).

  5. 5.

    et al. EB3, a novel member of the EB1 family preferentially expressed in the central nervous system, binds to a CNS-specific APC homologue. Oncogene 19, 210–216 (2000).

  6. 6.

    & Microtubule plus-end-tracking proteins: mechanisms and functions. Curr. Opin. Cell Biol. 17, 47–54 (2005).

  7. 7.

    & Microtubule plus end: a hub of cellular activities. Traffic 7, 499–507 (2006).

  8. 8.

    et al. CLASP1 and CLASP2 bind to EB1 and regulate microtubule plus-end dynamics at the cell cortex. J. Cell Biol. 168, 141–153 (2005).

  9. 9.

    et al. Structural determinants for EB1-mediated recruitment of APC and spectraplakins to the microtubule plus end. J. Cell Biol. 168, 587–598 (2005).

  10. 10.

    , & Melanophilin and myosin Va track the microtubule plus end on EB1. J. Cell Biol. 171, 201–207 (2005).

  11. 11.

    The roles of microfilament-associated proteins, drebrins, in brain morphogenesis: a review. J. Biochem. (Tokyo) 117, 231–236 (1995).

  12. 12.

    et al. Drebrin, a development-associated brain protein from rat embryo, causes the dissociation of tropomyosin from actin filaments. J. Biol. Chem. 269, 29928–29933 (1994).

  13. 13.

    , , & Evidence that an interaction between EB1 and p150Glued is required for the formation and maintenance of a radial microtubule array anchored at the centrosome. Mol. Biol. Cell 13, 3627–3645 (2002).

  14. 14.

    , , & EB1–microtubule interactions in Xenopus egg extracts: role of EB1 in microtubule stabilization and mechanisms of targeting to microtubules. Mol. Biol. Cell 13, 3614–3626 (2002).

  15. 15.

    & Characterization of functional domains of human EB1 family proteins. J. Biol. Chem. 278, 49721–49731 (2003).

  16. 16.

    , , , & Structural insights into the EB1–APC interaction. EMBO J. 24, 261–269 (2005).

  17. 17.

    et al. Key interaction modes of dynamic +TIP networks. Mol. Cell 23, 663–671 (2006).

  18. 18.

    , , , & Inhibition by drebrin of the actin-bundling activity of brain fascin, a protein localized in filopodia of growth cones. J. Neurochem. 66, 980–988 (1996).

  19. 19.

    , , & An analysis of an axonal gradient of phosphorylated MAP 1B in cultured rat sensory neurons. Eur. J. Neurosci. 8, 235–248 (1996).

  20. 20.

    Evidence for microtubule capture by filopodial actin filaments in growth cones. Neuroreport 2, 573–576 (1991).

  21. 21.

    , & Filopodia and actin arcs guide the assembly and transport of two populations of microtubules with unique dynamic parameters in neuronal growth cones. J. Cell Biol. 158, 139–152 (2002).

  22. 22.

    , & Polarity orientation of axonal microtubules. J. Cell Biol. 91, 661–665 (1981).

  23. 23.

    et al. Visualization of microtubule growth in cultured neurons via the use of EB3–GFP (end-binding protein 3–green fluorescent protein). J. Neurosci. 23, 2655–2664 (2003).

  24. 24.

    , , & Overexpression of drebrin A in immature neurons induces the accumulation of F-actin and PSD-95 into dendritic filopodia, and the formation of large abnormal protrusions. Mol. Cell Neurosci. 30, 630–638 (2005).

  25. 25.

    & Actions of cytochalasins on the organization of actin filaments and microtubules in a neuronal growth cone. J. Cell Biol. 107, 1505–1516 (1988).

  26. 26.

    , & Myosin II functions in actin-bundle turnover in neuronal growth cones. Nature Cell Biol. 8, 215–226 (2006).

  27. 27.

    , & The dynamic behavior of the APC-binding protein EB1 on the distal ends of microtubules. Curr. Biol. 10, 865–868 (2000).

  28. 28.

    et al. Quantification of integrin receptor agonism by fluorescence lifetime imaging. J. Cell Sci. 121, 265–271 (2008).

  29. 29.

    , & Modulation of microtubule dynamics by drugs: a paradigm for the actions of cellular regulators. Cell Struct. Funct. 24, 329–335 (1999).

  30. 30.

    , & Cloning of drebrin A and induction of neurite-like processes in drebrin-transfected cells. Neuroreport 3, 109–112 (1992).

  31. 31.

    & Breaking the neuronal sphere: regulation of the actin cytoskeleton in neuritogenesis. Nature Rev. Neurosci. 3, 694–704 (2002).

  32. 32.

    et al. Filopodial actin bundles are not necessary for microtubule advance into the peripheral domain of Aplysia neuronal growth cones. Nature Cell Biol. 9, 1360–1369 (2007).

  33. 33.

    et al. Filopodia are required for cortical neurite initiation. Nature Cell Biol. 9, 1347–1359 (2007).

  34. 34.

    , , & Transient expression of laminin immunoreactivity in the developing rat hippocampus. J. Neurocytol. 18, 451–463 (1989).

  35. 35.

    et al. Improved monomeric red, orange and yellow fluorescent proteins derived from Discosoma sp. red fluorescent protein. Nature Biotechnol. 22, 1567–1572 (2004).

  36. 36.

    et al. Tubulin tyrosination is a major factor affecting the recruitment of CAP-Gly proteins at microtubule plus ends. J. Cell Biol. 174, 839–849 (2006).

  37. 37.

    et al. Slit-mediated repulsion is a key regulator of motor axon pathfinding in the hindbrain. Development 132, 4483–4495 (2005).

  38. 38.

    , , , & Glycogen synthase kinase-3β phosphorylation of MAP1B at Ser1260 and Thr1265 is spatially restricted to growing axons. J. Cell Sci. 118, 993–1005 (2005).

  39. 39.

    , & Rat monoclonal antitubulin antibodies derived by using a new nonsecreting rat cell line. J. Cell Biol. 93, 576–582 (1982).

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We thank Britta Eickholt and her laboratory and the P.R.G.-W. laboratory for helpful discussions. We are grateful to Brigitte Keon for the gift of human drebrin E cDNA, Ewan Morrison for EB1 cDNA, Roger Tsien for CherryRFP cDNA, Britta Eickholt for drebrin–RFP, and Niels Galjart for polyclonal antibodies against CLASP 1, CLASP 2 and CLIP-170 and EB3 cDNA, and Matthias Krause for help with kymography and comments on the manuscript. This work was supported by grants from the Medical Research Council, the Royal Society and the Wellcome Trust. Sara Geraldo's PhD studentship is funded by Fundação para a Ciência e Tecnologia, Portugal.

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Author notes

    • John K. Chilton

    Present address: Institute of Biomedical and Clinical Science, Peninsula Medical School, Tamar Science Park, Research Way, Plymouth PL6 8BU, Devon, UK.

    • Sara Geraldo
    •  & Umme K. Khanzada

    These authors contributed equally to this work.


  1. The MRC Centre for Developmental Neurobiology, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK.

    • Sara Geraldo
    • , Umme K. Khanzada
    • , John K. Chilton
    •  & Phillip R. Gordon-Weeks
  2. The Randall Division of Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK.

    • Maddy Parsons


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U.K.K. performed the biochemical experiments shown in Fig. 1, P.R.G.-W. conducted the immunofluorescence experiments shown in Fig. 2, S.G. performed the live-cell imaging experiments shown in Figs 2 and 5 and the transfection experiments in Fig. 4, M.P. and S.G. conducted the FLIM experiments shown in Fig. 3, J.K.C. made EB1–RFP and EB3–RFP and conducted preliminary transfection experiments in neurons, P.R.G.-W. coordinated the whole project and wrote the manuscript, and all authors read and edited it.

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The authors declare no competing financial interests.

Corresponding author

Correspondence to Phillip R. Gordon-Weeks.

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