Active surface transport of metabotropic glutamate receptors through binding to microtubules and actin flow

1. J Cell Sci. 2003 Dec 15;116(Pt 24):5015-22.

Active surface transport of metabotropic glutamate receptors through binding to
microtubules and actin flow.

Serge A(1), Fourgeaud L, Hemar A, Choquet D.

Author information:
(1)Physiologie Cellulaire de la Synapse, CNRS UMR 5091, Institut François
Magendie, rue Camille saint Saëns, 33077 Bordeaux, Cedex, France.

Receptors for neurotransmitters are concentrated and stabilized at given sites
such as synapses through interactions with scaffolding proteins and cytoskeletal
elements. The transport of receptors first involves directed vesicular
trafficking of intracellularly stored receptors followed by their targeting to
the plasma membrane. Once expressed at the cell surface, receptors are thought to
reach their final location by random Brownian diffusion in the plasma membrane
plane. Here, we investigate whether the metabotropic glutamate receptor mGluR5
can also be transported actively on the cell surface. We used single particle
tracking to follow mGluR5 movement in real time at the surface of neuronal growth
cones or fibroblast lamellipodia, both of which bear a particularly active
cytoskeleton. We found that after a certain lag time mGluR5 undergoes directed
rearward transport, which depends on actin flow. On actin depolymerization,
directed movement was suppressed, but receptors still bound to a rigid structure.
By contrast, receptor transport and immobilization was fully suppressed by
microtubule depolymerization but favored by microtubule stabilization.
Furthermore, mGluR5 could be immunoprecipitated with tubulin from rat brains,
confirming the ability of mGluR5 to bind to microtubules. We propose that mGluR5
can be transported on the cell surface through actin-mediated retrograde
transport of microtubules. This process may play a role in receptor targeting and
organization during synapse formation or during glutamate-mediated growth cone
chemotaxis.

DOI: 10.1242/jcs.00822
PMID: 14625395 [Indexed for MEDLINE]

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