Abstract
The transcription factor erythroid 2 (NFE2)-related factor 2 (NRF2) is a key regulator of cellular homeostasis. Recent discoveries have identified agonists of NRF2 as inducers of broad cellular resistance to viral infection including SARS-CoV-2. Nevertheless, it is still unclear to what extent NRF2 itself is an inducer of anti-viral immunity and its downstream antiviral effectors have not been mapped. Here, we first demonstrate through specific genetic activation and silencing that NRF2 restricts SARS-CoV-2 replication. We then used a focused CRISPR-activation screen to map antiviral NRF2-inducible effector genes that restrict replication of SARS-CoV-2, Influenza A virus (IAV), Herpes Simplex virus 1 (HSV1) and Vaccinia virus (VACV). This approach allowed us to identify a range of antiviral effectors each of which restrict members of one or more virus families. Importantly, we identified the NRF2-inducible selective autophagy receptor p62/SQSTM1 as a broadly effective restriction factor across all the tested viruses. Importantly, p62 inhibited SARS-CoV-2 replication in cells treated with the lysosomal inhibitor bafilomycin A1, as well as in cells deficient in the autophagy protein ATG5. Similarly, p62 inhibited replication of HSV1 and IAV independently of ATG5 and ATG16L1 respectively. Thus, NRF2 restricts viral replication through a hitherto underappreciated network of antiviral restriction factors effective across multiple virus families. Importantly, we identify p62 as a broadly acting antiviral effector that restricts viral replication independently of canonical autophagy.