Figure 7.
F-actin–perturbing drugs alter the ensemble longitudinal diffusion of SSTR3 in the absence of Q-dot labeling. (A–C) 2P FRAPa experiments were performed as described in Fig. 5 (F and G), where SSTR3-PAGFP was photoconverted with 100-µs pulses of the Ti:S laser tuned to 850 nm. Groups of fluorescence relaxation curves obtained for cilia treated with vehicle (A), 3 µM jasplakinilode (B), or 0.1 µM latrunculin A (C) show that jasplakinolide treatment slows, whereas latrunculin treatment accelerates, relaxation. Each relaxation curve was fitted with the cilium surface ensemble diffusion model to obtain effective diffusion coefficients (Def). (D) Mean Def for each condition. ND, no drug (vehicle control). Error bars are SEM. Asterisks indicate significant differences from ND (P < 0.01) as determined by ANOVA with Bonferroni post hoc analysis. ND, n = 19 cilia; seven independent experiments; jasplakinolide, n = 17, three independent experiments; latrunculin A, n = 26; three independent experiments.