Fig. 4. Apg16L interacts with Apg5 and additional Apg16L monomers. (A) Apg16L interacts with Apg5. FLAG-tagged Apg16L and HA-tagged Apg5 were immunoprecipitated from HeLa cells transiently transfected with the indicated plasmids. The interaction of these co-transfected molecules was examined by western-blot analysis using anti-FLAG and anti-HA antibodies. (B) Apg16L forms a homo-oligomer. Wild-type ES cells and Apg5-deficient ES cells were transiently transfected with FLAG-tagged Apg16L and/or GFP-tagged Apg16L. Immunoprecipitates of GFP-Apg16L were examined for the co-immunoprecipitation of FLAG-Apg16L by western-blot analysis using anti-FLAG antibody. (C) Two-hybrid interactions of Apg16L-Apg5 and Apg16L-Apg16L. Interactions between Apg16L, Apg16L deletion constructs and Apg5 within transfected yeast cells were assessed for growth on SC —His —Trp —Leu plates containing 3 mM 3-amino-triazole.