FIGURE 2.

Recruitment of HSL to lipid droplets is dependent on the PAT protein composition of the droplet. Recruitment of HSL to perilipin-covered lipid droplets requires activation of PKA. CHO-K1 cells were co-transfected with HSL-CFP and a PAT fusion protein as follows: perilipin-YFP (A), ADFP-YFP (B), or LDSP-5-YFP (C). Cells were incubated overnight with 400 μm oleic acid. The following day, supplemental fatty acids were removed, and the cells were incubated with 5 μm triacsin C and no further additions (basal) or stimulated for 30 min with 10 μm forskolin, 1 mm IBMX, and 5 μm triacsin C (stimulated). Live cells were examined with a confocal microscope as in Fig. 1. Bar, 10 μm. Top, middle, and bottom rows show representative cells from 6 to 12 separate experiments.