Validation of ADAR1, MDA5, and RIG-I Knockouts

To confirm ADAR1 isoform specific KO and MDA5 KOs, CTRL A549s and various KOs cells were treated with 1000U/ml of universal type I IFN (PBL Assay Science) for 24 hours and lysed for western blot analysis. To confirm RIG-I KO, vector control and KO cells were infected with SeV for 16 hours and then lysed for western blot analysis. Whole cell lysates for western blot analysis was prepared using RIPA buffer (50 mM Tris pH 7.8, 150 mM NaCl, 0.1% SDS, 0.5% Sodium deoxycholate, 1% Triton X-100) containing protease inhibitors and quantified by Bradford protein assay. Approximately 50–80 μg of total protein was loaded on to SDS gel. Antibodies used for western blot analysis: ADAR1 (Abcam 88574; Santa Cruz sc-271854), MDA5 (Alexis Biochemicals AT113), RIG-I ((1C3 clone) [82 (link)]), IRF3 (Santa Cruz sc-9082), V5 (Bio-Rad), cleaved PARP (Cell Signaling 5625), total PARP (Cell Signaling 9542), and Ku (#K2882 Sigma).