Isolation and characterization of the ribonucleoprotein of influenza virus

Genome packaging in influenza A virus

“…However, again in counter-argument, a subsequent study disputed this, proposing instead that the structure were helices of M1 (Ruigrok et al, 1989). Furthermore, sedimentation analysis of material released from purified virus particles has so far failed to provide evidence for the existence of a packaging complex, with RNPs instead migrating at the approximate positions expected for their individual molecular masses (Compans et al, 1972;Duesberg, 1969;Krug, 1971;Pons et al, 1969). It should be noted, however, that these early experiments were all performed in buffer conditions that would not necessarily maintain structured RNA-RNA interactions.…”

The influenza virus RNA synthesis machine

“…[20][21][22][23] When isolated from purified virions, the genomic RNPs appear as ribbon-like, closed superhelical structures. [24][25][26][27] The structural features of these RNPs are in part due to the NP, as in vitro RNA-NP complexes resemble native RNPs 28 and even …”

Kinetics of Synthesis of Influenza Virus Ribonucleoprotein Structures

“…In the infected cell these RNA segments are transcribed into two forms of complementary plus-sense RNA (RNA+): a truncated copy which serves as messenger RNA (mRNA) to direct the synthesis of virus proteins and a complete transcript (cRNA) which serves as template for the synthesis of negative-sense virus RNA (Hay et al, 1977a, b). Where the various forms of virus-coded RNA are synthesized is unclear, but there is evidence that the cell nucleus is the probable site of transcription of virus mRNA (Armstrong & Barry, 1974;Taylor et al, 1977;Mark et al, 1978Mark et al, , 1979 Barrett et al, 1979).Within the virion the RNA segments are complexed with nucleoprotein (NP; Pons et al, 1969) to form separate ribonucleoprotein (RNP) complexes (Duesberg, 1969; Compans et al., 1972). In extracts from infected cells, RNPs containing both RNA + and RNA-have been found (Pons, 1971(Pons, , 1975 and it seems reasonable to suppose that all intracellular virus-induced RNA may be present in RNP complexes.…”