Configuration of viral ribonucleoprotein complexes within the influenza A virion.
The influenza A virus possesses an eight-segmented, negative-sense, single-stranded RNA genome (vRNA). Each vRNA segment binds to multiple copies of viral nucleoproteins and a small number of heterotrimeric polymerase complexes to form a rod-like ribonucleoprotein complex (RNP), which is essential for the transcription and replication of the vRNAs. However, how the RNPs are organized within the progeny virion is not fully understood. Here, by focusing on polymerase complexes, we analyzed the fine structure of purified RNPs and their configuration within virions by using various electron microscopies (EM). We confirmed that the individual RNPs possess a single polymerase complex at one end of the rod-like structure and that, as determined using immune EM, some RNPs are incorporated into budding virions with their polymerase-binding ends at the budding tip, whereas others align with their polymerase-binding ends at the bottom of the virion. These data further our understanding of influenza virus virion morphogenesis.
Division of Virology, Department of Microbiology and Immunology.
Yukihiko
Y
Sugita
Hiroshi
H
Sagara
Takeshi
T
Noda
Yoshihiro
Y
Kawaoka
D000818:Animals; D002642:Chick Embryo; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D007251:Influenza, Human / Q000821:virology; D008854:Microscopy, Electron; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
D012261:Ribonucleoproteins; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases