Weak effect of membrane diffusion on the rate of receptor accumulation at adhesive contacts
Biophysical Journal. 2005-11-01; 89(5): L40-L42
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1. Biophys J. 2005 Nov;89(5):L40-2. Epub 2005 Sep 16.
Weak effect of membrane diffusion on the rate of receptor accumulation at
Thoumine O(1), Saint-Michel E, Dequidt C, Falk J, Rudge R, Galli T,
Faivre-Sarrailh C, Choquet D.
(1)CNRS 5091, Université Bordeaux 2, Bordeaux, France.
To assess if membrane diffusion could affect the kinetics of receptor recruitment
at adhesive contacts, we transfected neurons with green fluorescent
protein-tagged immunoglobin cell adhesion molecules of varying length (25-180
kD), and measured the lateral mobility of single quantum dots bound to those
receptors at the cell surface. The diffusion coefficient varied within a
physiological range (0.1-0.5 microm(2)/s), and was inversely proportional to the
size of the receptor. We then triggered adhesive contact formation by placing
anti-green fluorescent protein-coated microspheres on growth cones using optical
tweezers, and measured surface receptor recruitment around microspheres by
time-lapse fluorescence imaging. The accumulation rate was rather insensitive to
the type of receptor, suggesting that the long-range membrane diffusion of
immunoglobin cell adhesion molecules is not a limiting step in the initiation of
PMID: 16169990 [Indexed for MEDLINE]