Fig. 2.

Expression of apoC-III-enhanced secretion of [³⁵S]apolipoprotein B-100 (apoB-100). A: Control (neo) and apoC-III-expressing cells (C3) were continuously labeled with [³⁵S]methionine/cysteine for 90 or 180 min in DMEM containing 20% FBS + 0.4 mM oleate. B and C: Cells were pulse labeled for 30 min and “chased” for up to 2 h in DMEM containing 20% FBS + 0.4 mM oleic acid (OA). D: Cells were continuously labeled for 90 or 180 min in the media without OA. At the indicated times, [³⁵S]apoB-100 (A, B, and D) and [³⁵S]apoE (C) were recovered from the cells and media by immunoprecipitation, resolved by SDS-PAGE, and subjected to fluorography. Radioactivity associated with [³⁵S]apoB and [³⁵S]apoE in cells and media was quantified. For the continuous labeling experiments (A and D), data are presented as cpm/mg cell protein. For the pulse-chase experiments (B and C), data are presented as percentage of initial counts, which are the counts associated with cell [³⁵S]apoB-100 or cell [³⁵S]apoE at the end of a 30 min pulse. The experiment was repeated, and similar results were obtained.