Figure 3.

RGS-12 (Regulator of G-protein signaling-12) co-localises with the S1P₁ in airway smooth muscle cells and reduces S1P-stimulation of the ERK-1/2 pathway. Airway smooth muscle cells were transfected with plasmid constructs encoding myc-tagged S1P₁ and hemagglutinin (HA) tagged RGS12 and stimulated with S1P (1 μM, 5 min). The data shows that RGS12 co-localises with S1P₁ in cytoplasmic vesicles. It remains to be determined whether S1P₁ in these vesicles is competent to signal. However, RGS12 dampens the activation of ERK-1/2 by S1P in these cells. The results are representative of three independent experiments.