The dialogue between membrane-bound and liquid membraneless organelles in influenza A vírus infection
Pr. Amorim is the head of the 'Cell Biology of Viral Infection' lab with international expertise of how viruses (e.g. Influenza Virus) exploit the membrane dynamics/ trafficking of the host cell to establish their infectious cycle. Pr. Amorim lab: https://gulbenkian.pt/ciencia/research-groups/mjamorim/
Viruses rely on being able to concentrate selected material spatiotemporally. In recent years, cell compartmentalization has undergone a paradigm shift. It became clear that material concentrates in specific locations without the need of a lipid barrier. The resultant membraneless compartments are supramolecular assemblies of multivalent proteins and nucleic acids with defined physical properties. Hence, assembly of membranelles organelles offers ideal solutions to organize reactions favouring viral infections. We found that during influenza A virus infection, progeny RNA, in the form of viral ribonucleoproteins (vRNPs), are concentrated in liquid organelles. Using correlative light and electron microscopy we found that RNPs clustered in structures devoid of delimiting membranes. Using fluorescence recovery after photobleaching we demonstrated that these structures are highly dynamic, and exchange material fast. Life cell tracking of RNPs in productive infections provided the deformative character of viral inclusions, their ability to adapt to several stimuli, the development close to the Endoplasmic Reticulum Exit Sites, and dependency on continuous ER-Golgi vesicular cycling. We propose that viral inclusions constitute dedicated sites for the assembly of influenza A virus genomes, constituted of a complex of eight different vRNPs.
Instituto Gulbenkian de Ciência, Oeiras, Portugal.
Domain 4 - UMR 144 - Cell Biology and Cancer