Recycling endosomes undergo rapid closure of a fusion pore on exocytosis in neuronal dendrites.

D. Jullie, D. Choquet, D. Perrais
Journal of Neuroscience. 2014-08-13; 34(33): 11106-11118
DOI: 10.1523/jneurosci.0799-14.2014

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1. J Neurosci. 2014 Aug 13;34(33):11106-18. doi: 10.1523/JNEUROSCI.0799-14.2014.

Recycling endosomes undergo rapid closure of a fusion pore on exocytosis in
neuronal dendrites.

Jullié D(1), Choquet D(1), Perrais D(2).

Author information:
(1)University of Bordeaux and National Center of Scientific Research,
Interdisciplinary Institute for Neuroscience, Coeducational Research Unit 5297,
F-33000 Bordeaux, France.
(2)University of Bordeaux and National Center of Scientific Research,
Interdisciplinary Institute for Neuroscience, Coeducational Research Unit 5297,
F-33000 Bordeaux, France .

Exocytosis of recycling endosomes (REs) represents the last step of receptor and
membrane recycling, a fundamental process involved in many aspects of cell
physiology. In neurons, it is involved in the control of cell polarity and
synaptic plasticity and is locally and tightly regulated. However, its molecular
mechanisms are still poorly understood. We have imaged single exocytosis events
of REs in rat hippocampal neurons in culture transfected with three types of
receptors tagged with the pH-sensitive GFP mutant superecliptic phluorin. We
found that exocytosis events are grouped into two categories: (1) short burst
events in which receptors diffuse into the plasma membrane in a few seconds; and
(2) long display events in which receptors remain visible and clustered after
exocytosis for many seconds. Display events are much rarer in non-neuronal cells,
such as fibroblasts and astrocytes. Using two-color imaging and fast
extracellular solution changes, we show that display events correspond to the
rapid opening and closing of a fusion pore (or « kiss-and-run ») with a median
opening time of 2.6 s, which restricts the diffusion of multiple receptor types
and bound cargo. Moreover, the RE marker Rab11 remains enriched after display
exocytosis events and controls the mode of RE exocytosis. Finally, a given RE can
undergo multiple rounds of display exocytosis. The last step of recycling can
thus be controlled in neurons for the selective delivery of receptors at the cell
surface.

Copyright © 2014 the authors 0270-6474/14/3411106-13$15.00/0.

DOI: 10.1523/JNEUROSCI.0799-14.2014
PMID: 25122907 [Indexed for MEDLINE]


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