SARS-CoV-2 hijacks p38β/MAPK11 to promote virus replication

SARS-CoV-2, the causative agent of the COVID-19 pandemic, drastically modifies infected cells in an effort to optimize virus replication. Included in this process is the activation of the host p38 mitogen-activated protein kinase (MAPK) pathway, which plays a major role in inflammation and is a central driver of COVID-19 clinical presentations. Inhibition of p38/MAPK activity in SARS-CoV-2-infected cells reduces both cytokine production and viral replication. Here, we combined genetic screening with quantitative phosphoproteomics to better understand interactions between the p38/MAPK pathway and SARS-CoV-2. We found several components of the p38/MAPK pathway impact SARS-CoV-2 replication and that p38β is a critical host factor that promotes viral replication and prevents activation of the interferon pathway. Quantitative phosphoproteomics uncovered several SARS-CoV-2 nucleocapsid (N) protein phosphorylation sites near the N-terminus that were sensitive to p38 inhibition. Similar to p38β depletion, mutation of these N residues was associated with reduced viral replication and increased activation of Type I interferon signaling. Taken together, this study reveals a unique proviral function for p38β that is not shared with p38α, and supports efforts to develop p38β inhibitors as a strategy towards developing a new class of COVID-19 therapies. methods