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Nanoscale segregation of actin nucleation and elongation factors determines dendritic spine protrusion
Author(s) -
Chazeau Anaël,
Mehidi Amine,
Nair Deepak,
Gautier Jérémie J,
Leduc Cécile,
Chamma Ingrid,
Kage Frieda,
Kechkar Adel,
Thoumine Olivier,
Rottner Klemens,
Choquet Daniel,
Gautreau Alexis,
Sibarita JeanBaptiste,
Gian Grégory
Publication year - 2014
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201488837
Subject(s) - biology , nucleation , elongation , dendritic spine , actin , spine (molecular biology) , microbiology and biotechnology , nanoscopic scale , evolutionary biology , biophysics , anatomy , neuroscience , nanotechnology , materials science , composite material , hippocampal formation , chemistry , organic chemistry , ultimate tensile strength
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 IRS p53 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 GTP ase 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.