FIG. 5.

Expression of a dominant inhibitory mutant of ARF6 in 3T3-L1 adipocytes inhibits the ability of endothelin-1 (ET-1) to stimulate hexose uptake. Six days following induction of GFP (a) or ARF6(T27N) (b) expression by infection with AdCre, 3T3-L1 adipocytes were treated with 10 nM endothelin 1 for 20 min or left in medium without agonist, and the uptake of 2-[³H]deoxyglucose was measured as in Fig. 4. The results shown are the means ± SEM of four independent experiments, each performed in triplicate. The asterisk denotes P = 0.0004 comparing endothelin 1-stimulated ARF6(T27N) 3T3-L1 adipocytes not infected and infected with AdCre. The endothelin 1-stimulated ARF6(T27N) 3T3-L1 adipocytes infected with AdCre are also significantly different (P = 0.02) compared to the endothelin 1-stimulated GFP cells infected with AdCre.