The ∆YXXΦ mutant is targeted to lipid droplets. (A) Huh7 cells were transfected with the indicated expression constructs. After 48 hr cells were treated with 1 mM fatty acids for 6 hr and then lipid droplets were stained with Nile Red. The 3a was stained with anti-3a antibodies. (B) Percent of the indicated 3a proteins in lipid droplets were quantified by determining colocalization coefficient in at least 50 different expressing cells as described. Data shown are representative of three different experiments.