Fig. 3. Sec23/Lst1p supports budding from synthetic liposomes. Liposomes (100 µg) extruded through 400 nm filters were used in budding reactions in the presence of Sar1p (85 µg/ml), Sec23/24p (85 µg/ml) or Sec23/Lst1p (85 µg/ml), Sec13/31p (100 µg/ml) and GMP-PNP (100 µM). Budded vesicles (fractions 11 and 12) were separated from large, coated liposomes (fractions 3–7) on linear sucrose gradients, and the distribution of lipid quantified by NBD-phospholipid fluorescence.