A genome-wide CRISPR screen identifies HuR as a regulator of apoptosis induced by dsRNA and viral infection

ABSTRACT: Cell death is an important host defense in response to viral infections. In this study,we performed an unbiased whole-genome CRISPR/Cas9 screen in A549 lung adenocarcinoma cells to identify potential regulators involved in cell death triggered dsRNA, a common byproduct of viral replication. Of several top candidate genes, we identified the RNA binding protein ELAV like protein 1 (ELAVL1) (ELAVL1, also called HuR) that encodes Hu antigen R (HuR). Depletion of HuR by gene editing led to less cell death induced by dsRNA. We further demonstrated that HuR regulated apoptosis, and the RNA recognition motif (RRM) 3 of HuR was essential for its proapoptotic function. HuR bound mRNA of anti-apoptotic gene BCL2. HuR depletion had no influence on BCL2 mRNA levels, but instead downregulated the BCL2 translation. Polysome fractionation studies showed that HuR retarded the BCL2 mRNA in the non-translating pool of polysomes. Moreover, protection from dsRNA-induced apoptosis by HuR depletion required the presence of BCL2, indicating that the proapoptotic function of HuR is executed by suppressing BCL2. Consistently, HuR regulated apoptosis induced by infection of encephalomyocarditis or Semliki Forest virus, two unrelated positive strand RNA viruses. Collectively, our work identified a suite of proteins that regulate dsRNA-induced cell death, and elucidated the mechanism by which HuR acts as a pro-apoptotic factor.

ORGANISM(S): Homo sapiens

PROVIDER: GSE165625 | GEO | 2021/01/28

REPOSITORIES: GEO