Figure 1.

Some MpPR-1 family members complement the sterol export defect of yeast mutants lacking Pry function. A, heme and Say1 deficient double mutant cells (hem1Δ say1Δ) containing either no plasmid (−), an empty plasmid (Empty), or a plasmid-borne copy of Pry1 or of the indicated MpPR-1 family member were cultivated in the presence of radiolabeled [¹⁴C]cholesterol. Lipids were extracted from the cell pellet (P) and the culture supernatant (S), separated by TLC, and visualized by phosphorimaging. The position of free cholesterol (FC), CA, steryl esters (STE) and unidentified lipids (*) are indicated to the right. The experiment was repeated five times with similar results. B, quantification of the export of CA. The export index indicates the relative levels of CA exported by the cells (the ratio between extracellular CA and the sum of intracellular and extracellular CA). The data represent the means ± S.D. of five independent experiments. Asterisks denote statistical significance of the export phenotype relative to hem1Δ say1Δ double mutant cells. ***, p < 0.0001. n.s., not significant.