[Changes in the structure of the M- and NS-genes in the process of influenza virus attenuation].
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Animals↗
Biomedical subjects
A G Kurmanova
Publications and source records attributed to A G Kurmanova.
On the origin of the H1N1 (A/USSR/90/77) influenza virus.
The influenza virus H1N1 (the A/USSR/90/77 strain) that reappeared in 1977 after the H1N1 influenza viruses had disappeared from the human population, is compared with the A/FM/1/47 and the A/FW/1/50 influenza viruses by the method of oligonucleotide mapping of individual segments of the viral RNAs. Seven genes of the A/USSR/90/77 virus appear to be very similar to the corresponding genes of the A/FW/1/50 virus, whereas the gene coding for the M protein displays considerable homology to the corresponding gene of the A/FM/1/47 virus. The data demonstrate that the A/USSR/90/77 strain is a recombinant virus.
Genes, Viral↗
[Recombination origin of the epidemic A/USSR/90/77 strains of influenza virus].
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Base Sequence↗
[Ribosome-inactivating lectins from plants].
There is a heterogeneous group of plant proteins which are able to enzymatically inactivate ribosomes by depurination of an invariant adenine from the 28 S ribosomal RNA. Some of these proteins are heterodimers having a lectin subunit which is joined by disulfide bond to the enzymatic subunit. Ricin and abrin which are among the most toxic substances known belong to the last group. This review focuses on the structure of the heterodimeric plant ribosome-inactivating proteins, the way of their action on ribosome, biosynthesis, intracellular trafficking, and their possible usage in medicine.
Abrin↗
[Changes in the composition of double-stranded sequences of poly(A)-containing RNA in cell cytoplasm during hormonal induction].
Double-stranded segments (c-ds) have been studied in the poly(A)+ cytoplasmic rat liver RNA. Duplexes about 40 base pairs long have been shown to be of intermolecular character and originate from the interaction between ss-RNA and complementary regions of the poly(A)-containing RNA molecules. Shorter ds-sequences are, mainly, of intramolecular nature. Double-stranded sequences of different length differ also in their oligonucleotide composition, according to fingerprint analysis data. Under the action of cortisone, only several kinds of double-stranded sequences have been demonstrated to increase in the population of cytoplasmic poly(A)+RNA. The function of ds-regions in the hormonal regulation of gene expression is suggested.
Animals↗
[Genetic recombination between natural isolates of influenza virus serotypes H1N1 and H3N2].
Oligonucleotide mapping of individual genes was used for search of possible genetic recombinants between natural isolates of influenza H1N1 and H3N2 viruses isolated in the USSR in 1977-1979. No antigenic hybrids and recombinants with the antigenic structure H3N2 were found, however, it was shown that isolates of H1N1 viruses of 1979 (the A/USSR/61/79 strain) might represent genetic recombinants carrying genes P1 + P2 from H3N2 viruses, the M-gene of the USSR/61/79 virus being closest in its structure to the analogous gene of the earliest isolate of H3N2 viruses, namely A/Hong Kong/1/68. Possible selective advantages of virus recombinants having M-genes from viruses of a different serotype are discussed.
Genes, Viral↗
[Genetic variability of epidemic strains of influenza virus serotypes H1N1 and H3N2 during antigenic drift].
Data are presented on structural variability of individual genes of selected variants of epidemic influenza viruses H1N1 (1977-1979) and H3N2 (1968-1979) in the course of antigenic drift obtained by oligonucleotide mapping. Six out of 8 genes of H1N1 viruses were found to be more variable than the corresponding genes of H3N2 viruses. Only HA and NS genes of H3N2 viruses underwent greater structural changes as compared with the analogous genes of H1N1 viruses. In viruses of both serotypes, most variable were the genes coding for hemagglutinin and matrix protein. Possible causes of greater structural variability of the matrix protein gene in the course of antigenic drift are discussed.
Antigenic Variation↗
[Structural changes in influenza virus RNA during its attenuation].
Changes in structures of only two genes of influenza virus--M and NS genes were found during virus attenuation by the method of oligonucleotide mapping. Such changes were observed in virulent and attenuated viruses (passages 10-23 in chick embryos) by comparing intermediate variants of the virus (passages 11-16 in chick embryos). These results allow us to conclude the important role of these genes in virus attenuation and in connection with virulence of the virus.
Animals↗
[Analysis of structural divergence of H1N1 serotype influenza virus individual genes].
A comparative structural analysis of H1N1 influenza virus isolated in 1977 (the A/USSR/90/77 strain) and H1N1 isolates of 1947 (the A/FM/1/47 strain) and 1950 (the A/FW/1/50 strain) have been carried out by oligonucleotide mapping of individual viral RNA segments. Seven of eight genes of A/USSR/90/77 strain have a high degree of homology with corresponding genes of A/FW/1/50 strain, especially the genes coding the NP and P2 proteins. At the same time the gene coding matrix (M) protein has higher structural similarity to the corresponding gene of A/FM/1/47 strain. Based on the results presented one may conclude that the A/USSR/90/77 epidemic strain is a recombinant virus.
DNA, Viral↗