Figure 4
From: Germline variants of ATG7 in familial cholangiocarcinoma alter autophagy and p62
ATG7 p.R659* is a loss-of-function mutation. (a) The predicted structure of ATG7 contains an N-terminal domain (NTD), linker region, adenylation domain (AD), and extreme C-terminal domain (ECTD). The p.R659* (R659*) and p.D522E (D522E) mutations are indicated in isoform 1 of the ATG7 protein. (b) Predicted functional impact of ATG7 p.R659* mutation. Wildtype ATG7 and ATG3 conjugate ATG8 proteins such as LC3 with phosphatidylethanolamine (PE). We determined that the ATG7 R659* mutant lacks PE conjugation activity to LC3 as a result of the ECTD truncation. (c) Expression of ATG7 WT isoform 1 (iso1) and D522E restored the lipidation of LC3B whereas expression of ATG7 R659*, C572S, or WT isoform 2 (iso2) failed to lipidate LC3B from LC3B-I to LC3B-II. A Myc-tag was used to detect the expression of exogenous ATG7 from various vectors. A GFP expressing vector was used as a negative control. GAPDH was used as the loading control. Original blots are presented in Supplementary Fig. S9 online.
