Deficient ubiquitin-like conjugation activity in Atg7−/− erythroid cells. (A) Western blot analyses of LC3, GABARAP (GRP), GATE-16 (GT16), Atg12, Ter119, BCL-XL, Beclin-1, and β-actin in expanded E14.5 fetal liver cells undergoing differentiation in culture for 2 days. The upper LC3 band corresponds to the unconjugated form of LC3, and the lower band corresponds to the lipid conjugated form of LC3. This same is true for the other Atg8 homologs, GABARAP and GATE-16. Wild-type murine embryonic fibroblasts (MEF) provide a positive control for the position of the unconjugated and conjugated proteins. Genotypes and days in culture are indicated at the top. (B) Western blot analyses of Atg7, NIX, Beclin-1, and β-actin in primary E14.5 fetal liver cells. NIX protein is expressed as 2 isoforms in erythroid cells, a full-length monomeric form (top band), and a shorter isoform, which has not been fully characterized (bottom band). Beclin-1 is provided as a loading control. Genotypes are indicated at the top.
