Figure 7.

Knockdown of SPL expression in MIN6 cells has no significant effect on agonist-induced M3R internalization. MIN6 cells were electroporated with SPL-1 siRNA or scrambled control siRNA (Con-2), as described in detail in Materials and Methods. After 2 d, cells were treated with the agonist OXO-M (100 μM) at 37°C for the indicated periods of time. Cell surface M3R expression was determined by incubating cells with a saturating concentration (2 nM) of [³H]NMS, a membrane-impermeable muscarinic radioligand. In each individual experiment, M3R densities before agonist addition were set equal to 100% (see text for absolute receptor densities). Data are given as means ± se of 3 independent experiments.