The Feat of Packaging Eight Unique Genome Segments.
Influenza A viruses (IAVs) harbor a segmented RNA genome that is organized into eight distinct viral ribonucleoprotein (vRNP) complexes. Although a segmented genome may be a major advantage to adapt to new host environments, it comes at the cost of a highly sophisticated genome packaging mechanism. Newly synthesized vRNPs conquer the cellular endosomal recycling machinery to access the viral budding site at the plasma membrane. Genome packaging sequences unique to each RNA genome segment are thought to be key determinants ensuring the assembly and incorporation of eight distinct vRNPs into progeny viral particles. Recent studies using advanced fluorescence microscopy techniques suggest the formation of vRNP sub-bundles (comprising less than eight vRNPs) during their transport on recycling endosomes. The formation of such sub-bundles might be required for efficient packaging of a bundle of eight different genomes segments at the budding site, further highlighting the complexity of IAV genome packaging.
Institute of Virology, University Medical Center Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany. sebastian.giese@uniklinik-freiburg.de.
Sebastian
S
Giese
Institute of Virology, University Medical Center Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany. hardin.bolte@uniklinik-freiburg.de.|Spemann Graduate School of Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany. hardin.bolte@uniklinik-freiburg.de.
Hardin
H
Bolte
Institute of Virology, University Medical Center Freiburg, Hermann-Herder-Strasse 11, 79104 Freiburg, Germany. martin.schwemmle@uniklinik-freiburg.de.
Martin
M
Schwemmle
D009980:Influenza A virus / Q000502:physiology*; D012261:Ribonucleoproteins / Q000378:metabolism; D019065:Virus Assembly
D012261:Ribonucleoproteins
formation of genome sub-bundles; genome packaging; influenza virus; packaging sequences; vRNP