Nanoscale segregation of actin nucleation and elongation factors determines dendritic spine protrusion.

Anaël Chazeau, Amine Mehidi, Deepak Nair, Jérémie J Gautier, Cécile Leduc, Ingrid Chamma, Frieda Kage, Adel Kechkar, Olivier Thoumine, Klemens Rottner, Daniel Choquet, Alexis Gautreau, Jean‐Baptiste Sibarita, Grégory Giannone
EMBO J.. 2014-10-07; 33(23): 2745-2764
DOI: 10.15252/embj.201488837

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1. EMBO J. 2014 Dec 1;33(23):2745-64. doi: 10.15252/embj.201488837. Epub 2014 Oct 7.

Nanoscale segregation of actin nucleation and elongation factors determines
dendritic spine protrusion.

Chazeau A(1), Mehidi A(1), Nair D(1), Gautier JJ(2), Leduc C(3), Chamma I(1),
Kage F(4), Kechkar A(1), Thoumine O(1), Rottner K(5), Choquet D(1), Gautreau
A(2), Sibarita JB(1), Giannone G(6).

Author information:
(1)Interdisciplinary Institute for Neuroscience, University Bordeaux UMR 5297,
Bordeaux, France CNRS, Interdisciplinary Institute for Neuroscience UMR 5297,
Bordeaux, France.
(2)CNRS UPR3082, Laboratoire d’Enzymologie et Biochimie Structurales,
Gif-sur-Yvette Cedex, France.
(3)University Bordeaux, LP2N, Talence, France CNRS & Institut d’Optique, LP2N,
Talence, France.
(4)Division of Molecular Cell Biology, Zoological Institute, Technical University
Braunschweig, Braunschweig, Germany.
(5)Division of Molecular Cell Biology, Zoological Institute, Technical University
Braunschweig, Braunschweig, Germany Helmholtz Centre for Infection Research,
Braunschweig, Germany.
(6)Interdisciplinary Institute for Neuroscience, University Bordeaux UMR 5297,
Bordeaux, France CNRS, Interdisciplinary Institute for Neuroscience UMR 5297,
Bordeaux, France .

Comment in
EMBO J. 2014 Dec 1;33(23):2737-9.

Actin dynamics drive morphological remodeling of neuronal dendritic spines and
changes in synaptic transmission. Yet, the spatiotemporal coordination of actin
regulators in spines is unknown. Using single protein tracking and
super-resolution imaging, we revealed the nanoscale organization and dynamics of
branched F-actin regulators in spines. Branched F-actin nucleation occurs at the
PSD vicinity, while elongation occurs at the tip of finger-like protrusions. This
spatial segregation differs from lamellipodia where both branched F-actin
nucleation and elongation occur at protrusion tips. The PSD is a persistent
confinement zone for IRSp53 and the WAVE complex, an activator of the Arp2/3
complex. In contrast, filament elongators like VASP and formin-like protein-2
move outwards from the PSD with protrusion tips. Accordingly, Arp2/3 complexes
associated with F-actin are immobile and surround the PSD. Arp2/3 and Rac1 GTPase
converge to the PSD, respectively, by cytosolic and free-diffusion on the
membrane. Enhanced Rac1 activation and Shank3 over-expression, both associated
with spine enlargement, induce delocalization of the WAVE complex from the PSD.
Thus, the specific localization of branched F-actin regulators in spines might be
reorganized during spine morphological remodeling often associated with synaptic
plasticity.

© 2014 The Authors.

DOI: 10.15252/embj.201488837
PMCID: PMC4282554
PMID: 25293574 [Indexed for MEDLINE]


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