Fig. 5. Apg16L forms a 800 kDa protein complex with Apg12-Apg5. (A) Apg16L is present primarily in the cytosol. ES cell homogenate (Total) was fractionated into an initial pellet (P13) and a subsequent pellet (P100) and supernatant (S100) fractions by differential centrifugation. These fractions were analysed by immunoblotting using antibodies against Apg5 and Apg16L. (B) Apg12-Apg5 and Apg16L form a 800 kDa complex. S100 fractions of tissue homogenates of liver and brain, and cell lysates of wild-type and APG5^-/- ES cells were separated by size exclusion chromatography on a Superose 6 column. Each fraction was subjected to immunoblotting using anti-Apg5 and anti-Apg16L antibodies. Positions of the molecular mass standards (in kDa) are shown. V, void fraction.