The R353G mutation reduces CD4-Q2C expression in the axon.

<p>(A) Permeabilized immunostaining of wild-type (WT) or R353G mutant CD4-Q2C in hippocampal neurons (DIV 7–8) cotransfected with GFP. Neuronal soma and dendrites were identified by MAP2 immunostaining (middle). The insets in the representative inverted images of total CD4-Q2C show the initial segment (AIS) and distal segment (A) of the MAP2-negative axon in transfected neurons. Camera lucida drawings (lower) of the neuronal images (upper) show the soma and dendrites (gray) and an axon (black). The R353G mutation reduced but did not abolish total (surface and intracellular) expression of CD4-Q2C from the axon. Scale bars are 20 µm. (B) Background subtracted, mean intensity of total CD4 fluorescence in the AIS, distal axons, soma, and major dendrites. AU, arbitrary unit. The sample number for each construct used was as follows: WT (n = 23), R353G (n = 18), and untransfected (n = 15). AU, arbitrary unit. Ave ± SEM (**p<0.01, ***p<0.001).