Fig. 7.

Ligand rank order is not conserved for cAMP E _max values and βarr-dependent internalization in neurons. The proportion of ligand-induced DOR internalization that was blocked by interfering with the activity of neuronal βarr, PKC or GRK2 was calculated to establish the following rank orders: a ligand ability to engage GRK-2-dependent internalization (n = 5), b ligand ability to engage PKC-dependent internalization (n = 4), and c βarr-dependent-internalization (n = 4). Results are expressed as mean ± SEM of the percentage of internalization blocked by interfering with the activity of each of the regulatory proteins. Data were analyzed by means of one-way ANOVA with Bonferroni correction for multiple comparisons and results appear in the figure. d Rank order or ligand E _max values in cyclase assays (n = 7–9). Results are expressed as in Tables 1 and 2, which also show details of statistical comparisons