FIGURE 7.

GRK2 does not affect recycling or basal plasma membrane expression of mGluR5. A, shown is a representative immunoblot for cell surface biotin-labeled mGluR5 (upper panel) in striatal neurons infected with either GFP or GRK2 adenovirus and stimulated with 10 μm DHPG for 10 min and allowed to recover for 10 or 30 min. Total cell lysates (50 μg) were used to determine mGluR5 total cell expression (input) for each sample (lower panel). B, graph shows the densitometric analysis of biotin-labeled cell surface mGluR5 immunoblot. Data represent the mean ± S.E. of four independent experiments, normalized to cell surface mGluR5 in neurons not treated with agonist. Asterisk indicates significant difference as compared with mGluR5 cell surface expression in striatal neurons expressing endogenous levels of GRK2 (p < 0.05). C, graph shows the densitometric analysis of biotin-labeled cell surface mGluR5 immunoblot from unstimulated neurons. Data represent the mean ± S.E. of five independent experiments, normalized to total mGluR5 expression for each sample and expressed as percentage of cell surface mGluR5 in neurons infected with GFP adenovirus.