FIGURE 5.

Triglyceride synthesis is correlated with ARV1 expression in HEK293 cells. Human hARV1 expression was suppressed using small hairpin RNA-mediated transcript degradation. HEK293 stable cell lines with altered expression were created through transfection and antibiotic selection and assessed for hARV1 mRNA level by Northern blot (A). Relative abundance of ARV1 mRNA was expressed as a ratio to glyceraldehyde-3-phosphate dehydrogenase (G3PDH). ARV1 knockdown resulted in reduced levels of triglyceride (B) with no detectable change in phospholipid synthesis (C), as assessed by [³H]glycerol incorporation. Stable HEK293 cell lines with increased expression of human ARV1 were created through transfection with hARV1-EGFP, maintained in DMEM + 400 μg/ml geneticin, and assessed by immunoblotting of total extracts with antisera against GFP (D). Control cells were transfected with an enhanced GFP empty vector. hARV1-EGFP cells have increased triglyceride and phospholipid levels (E and F) compared with control. Asterisks denote statistical significance (*, p < 0.05) as determined by unpaired t test (mean ± S.D., n = 3).