GFP insertion at the N-terminus of PSD-95 prevents the D1R-PSD95 interaction-induced D1R surface delivery.

<p>(<b>A</b>) Schematic representation of the interaction between PSD-95, characterized by its PDZ binding (squares), SH3 and GK domains (rounds), and D1R (<i>upper panel</i>). Note that the interaction occurs at the N-terminus domain of PSD95. Two variants of PSD95 were transfected in HEK cells: PSD95-CT_GFP that contains a GFP at its C-terminus and PSD95-NT_GFP that contain a GFP at its N-terminus (insertion at amino acid position 32). HEK cells were transfected with D1R-CFP and either PSD95-CT_GFP or PSD95-NT_GFP (do not bind to D1R). The surface content of D1R was measured by immuncytochemistry in the transfected cells (<i>lower panel</i>). (<b>B</b>) Line scan (white line in A) of the immunofluorescence of surface D1R from a HEK cell transfected with D1R alone. Note that D1R are enriched at the plasma membrane. (<b>C</b>) Quantification of the surface content of D1R in the various conditions. The co-expression of PSD95-CT_GFP increases the surface content of D1R (P<0.05), whereas the co-expression of PSD95-NT_GFP has no significant effect on the surface content of D1R (P>0.05).</p