Phosphoproteomic-based kinase profiling early in influenza virus infection

Although annual epidemics of seasonal influenza affect around 10% of the global population, current treatment options are limited and development of new antivirals is urgently needed. Here, using state-of-the-art quantitative phosphoproteomics, we reveal the unique phosphoproteome dynamics that occur in the host cell within minutes of influenza A virus (IAV) infection. Based on this virus-induced phosphorylation signature, we uncover cellular kinases required for the observed signalling pattern and find that inhibition of selected candidates, such as the G protein-coupled receptor kinase 2 (GRK2), leads to decreased IAV replication. As GRK2 has emerged as drug target in heart disease, we focus on its role in IAV infection and show that it is required for viral entry at the stage of uncoating. Replication of seasonal and pandemic IAVs is severely decreased by specific GRK2 inhibitors in primary human airway cultures and in an animal model. Our study reveals the IAV-induced changes to the cellular phosphoproteome and identifies GRK2 as a crucial node of the kinase network that enables IAV replication.