Figure 4.

Endogenous trunSM partitions to lipid droplet fractions. HeLa cells were transfected with the indicated constructs for 24 h, and treated with 300 μM oleic acid for 16 h. Lipid droplet (LD), cytosol (cyto.), pellet, and total fractions were collected, and levels of calnexin (endoplasmic reticulum marker), ABHD5 (LD marker), GAPDH (cytosol marker), and proteins of interest were determined by immunoblotting. Graph depicts quantification of LD partitioning, expressed as the ratio between protein levels in LD and membrane fractions, normalized to that of ABHD5. Data presented as mean ± SEM from n = 3 to 4 independent experiments (∗p ≤ 0.05; two-tailed ratio paired t test versus full-length endogenous [endog.] SM or full-length [HA]₃-SM-V5). ABHD5, abhydrolase domain-containing-5; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; SM, squalene monooxygenase; trunSM, truncated SM.