Gain-of-function genetic screening identifies the antiviral function of TMEM120A via STING activation

Shuo Li,Nianchao Qian,Wenhong Zu,Chao Jiang,Mamie Li,Xu Tan,Stephen J Elledge,Anthony Liang

doi:10.1038/s41467-021-27670-1

Abstract

Zika virus (ZIKV) infection can be associated with neurological pathologies, such as microcephaly in newborns and Guillain-Barre syndrome in adults. Effective therapeutics are currently not available. As such, a comprehensive understanding of virus-host interactions may guide the development of medications for ZIKV. Here we report a human genome-wide overexpression screen to identify host factors that regulate ZIKV infection and find TMEM120A as a ZIKV restriction factor. TMEM120A overexpression significantly inhibits ZIKV replication, while TMEM120A knockdown increases ZIKV infection in cell lines. Moreover, Tmem120a knockout in mice facilitates ZIKV infection in primary mouse embryonic fibroblasts (MEF) cells. Mechanistically, the antiviral activity of TMEM120A is dependent on STING, as TMEM120A interacts with STING, promotes the translocation of STING from the endoplasmic reticulum (ER) to ER-Golgi intermediate compartment (ERGIC) and enhances the phosphorylation of downstream TBK1 and IRF3, resulting in the expression of multiple antiviral cytokines and interferon-stimulated genes. In summary, our gain-of-function screening identifies TMEM120A as a key activator of the antiviral signaling of STING.

Highlights

Zika virus (ZIKV) infection can be associated with neurological pathologies, such as microcephaly in newborns and Guillain-Barre syndrome in adults
Each open reading frame (ORF) in the library is barcoded with 25 base-pairs random sequences, whose identity has been pre-determined with deep sequencing
Huh[7] cells, which are permissive to ZIKV infection[22], were transduced with the lentiviral ORFs library (400 million cells at MOI = 0.2), selected with puromycin, and infected with ZIKV at an MOI of 5

Summary

Introduction

Zika virus (ZIKV) infection can be associated with neurological pathologies, such as microcephaly in newborns and Guillain-Barre syndrome in adults. We report a human genome-wide overexpression screen to identify host factors that regulate ZIKV infection and find TMEM120A as a ZIKV restriction factor. Host proteins with antiviral functions (restriction factors) are mobilized to defend against virus infection, in part through activation of the interferon signaling pathway. Proteomic analysis and ZIKV-host protein interactomes identified neural cell adhesion molecule (NCAM1) as a potential ZIKV receptor[17], interaction between ZIKV NS4A and ANKLE2, which is a gene linked to hereditary microcephaly[18], and Dicer as a ZIKV restriction factor[19]. We utilize a recently developed genome-wide lentiviral open reading frame (ORF) overexpression library to screen for host factors related to ZIKV infection. We identify a ZIKV restriction factor TMEM120A and reveal that it functions as a key activator of STING, potentiating STING-dependent innate immune responses to inhibit multiple RNA and DNA viruses

Methods

Results

Conclusion