Figure 2.

PDAT activity in yeast microsomes, as visualized by autoradiogram of neutral lipid products separated on TLC. Microsomal membranes from the wild-type yeast strain FY1679 (lanes 1–3), a congenic yeast strain [FVKT004–04C(AL)] that is disrupted for YNR008w (lane 4), or the same disruption strain transformed with the plasmid pUS1, containing the YNR008w gene behind its native promoter (lane 5), were assayed for PDAT activity. As substrates, we used 2 nmol of sn-1-oleoyl-sn-2-[¹⁴C]ricinoleoyl-PC together with either 5 nmol of dioleoyl-DAG (lanes 2, 4, and 5) or rac-oleoyl-vernoloyl-DAG (lane 3). The enzymatic assay and lipid analysis were performed as described in Materials and Methods. Abbreviations: 1-OH-TAG, monoricinoleoyl-TAG; 1-OH-1-ep-TAG, monoricinoleoyl-monovernoloyl-TAG; OH-FA, unesterified ricinoleic acid.