Surface biotinylation of primary neurons to monitor changes in AMPA receptor surface expression in response to kainate receptor stimulation.

Here, we detail a surface biotinylation technique used to label surface-expressed proteins in primary neuronal cultures. Surface proteins are labeled with membrane-impermeant Sulfo-NHS-SS-biotin, and isolated by pull-down with streptavidin beads followed by western blotting to measure levels of surface expression of the protein of interest under different conditions. We have used this approach extensively to monitor activity-dependent changes in α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and kainate receptor (KAR) subunits. However, this protocol can be used to investigate any surface-expressed protein. For complete details on the use and execution of this protocol, please refer to Nair et al. (2021).