Old dog, new tricks: Influenza A virus NS1 and in vitro fibrillogenesis

A A Shaldzhyan1, Y A Zabrodskaya2, I L Baranovskaya3

  • 1Smorodintsev Research Institute of Influenza, Russian Ministry of Health, 197376, Prof. Popov 15/17, St. Petersburg, Russia; Petersburg Nuclear Physics Institute Named By B. P. Konstantinov of the National Research Center "Kurchatov Institute", 188300, mkr. Orlova Roshcha 1, Gatchina, Russia.

Biochimie
|July 17, 2021
PubMed

The influenza NS1 protein is involved in suppression of the host immune response. Recently, there is growing evidence that prion-like protein aggregation plays an important role in cellular signaling and immune responses. In this work, we obtained a recombinant, influenza A NS1 protein and showed that it is able to form amyloid-like fibrils in vitro. Using proteolysis and subsequent mass spectrometry, we showed that regions resistant to protease hydrolysis highly differ between the native NS1 form (NS1-N) and fibrillar form (NS1-F); this indicates that significant structural changes occur during fibril formation. We also found a protein fragment that is capable of inducing the process of fibrillogenesis at 37 °C. The discovery of the ability of NS1 to form amyloid-like fibrils may be relevant to uncovering relationships between influenza A infection and modulation of the immune response.