Analysis of alpha 3 GlyR single particle tracking in the cell membrane

作者：Notelaers Kristof; Rocha Susana; Paesen Rik; Smisdom Nick; De Clercq Ben; Meier Jochen C; Rigo Jean Michel; Hofkens Johan; Ameloot Marcel^*

来源：Biochimica et Biophysica Acta-Molecular Cell Research, 2014, 1843(3): 544-553.

DOI：10.1016/j.bbamcr.2013.11.019

• Glycine receptor
• Alpha3 subunit
• RNA splicing
• Single particle tracking
• Confined motion
• Directed motion

Single particle tracking (SPT) of transmembrane receptors in the plasma membrane often reveals heterogeneous diffusion. A thorough interpretation of the displacements requires an extensive analysis suited for discrimination of different motion types present in the data. Here the diffusion pattern of the homomeric alpha 3-containing glycine receptor (GlyR) is analyzed in the membrane of HEK 293 cells. More specifically, the influence of the alpha 3 RNA splice variants alpha 3K and alpha 3L on lateral membrane diffusion of the receptor is revealed in detail. Using a combination of ensemble and local SPT analysis, free and anomalous diffusion parameters are determined. The GlyR alpha 3 free diffusion coefficient is found to be 0.13 +/- 0.01 mu m(2)/s and both receptor variants display confined motion. The confinement probability level and residence time are significantly elevated for the alpha 3L variant compared to the alpha 3K variant. Furthermore, for the alpha 3L GlyR, the presence of directed motion was also established, with a velocity matching that of saltatory vesicular transport. These findings reveal that alpha 3 GlyRs are prone to different types of anomalous diffusion and reinforce the role of RNA splicing in determining lateral membrane trafficking.

• 出版日期2014-3