PubMed Health⌕ Search

Biomedical subjects

L V Uryvaev

Publications and source records attributed to L V Uryvaev.

81 records · Page 5Linked to original sources
PubMedDate not supplied

[Analysis of the primary structure of segments of the Karelian fever virus genome].

Primary structure of two parts of Karelian fever virus (KFV) genome (29-57 nt and 10507-11591 nt) cloned in recombinant plasmids has been studied and compared with that of Sindbis (HRSP strain) and Ockelbo viruses. Fifty-four nucleotide substitutes were revealed in the sequenced parts of KFV genome including partially 5' and 3'-nontranslated sites ( a total of 1613 nucleotides, or approximately 13.8% of the genome length), in comparison with the Sindbis virus prototype HRSP strain, this being in good correlation with strain variability. Eighteen nucleotide substitutes (96.4% homology) were detected in the NSP1 gene site (60-557 nt) of KFV in comparison with Sindbis virus and only 5 substitutes (98.8% homology) vs. Ockelbo virus. These data on primary structure of KFV genome reliably and unambiguously indicate the appurtenance of this virus to Sindbis-like viruses.

Alphavirus↗
PubMedDate not supplied

[Sindbis viruses of various geographic origin and differentiation of them from Western equine encephalomyelitis viruses using the polymerase chain reaction].

Comparison of Sindbis virus strains isolated in different regions of the world (in Africa, Australia, and Europe, including Russia and its nearest neighbors) in the polymerase chain reaction (PCR) by the primary gene structure of proteins NSP1 and E1 and in the neutralization test showed the greatest similarity between geographically close strains isolated in Northern Europe (KFL, Karelia, 1381 and 1388, Estonia). Sindbis strains AR339 and Babanki isolated in Africa were similar to each other and to strains from Northern Europe by the examined gene sites but different from the Northern variants in the neutralization test. Geographically remote strains F-720 (Armenia and Southern Europe) and Whataroa (New Zealand) were close to Sindbis virus from Africa and Northern Europe by only one of the genes examined (F-720 by NSP1 and Whataroa by E1). PCR was carried out using oligonucleotide primers containing nucleotide sequences identical to genes NSP1 and E1 sites of Sindbis strains HRSP, Okelbo, and KFL, but different from gene sites of other known representatives of alphaviruses by at least 5 positions. PCR analysis showed that the appurtenance of the geographic variants to Sindbis group can be ascertained only after investigating the homology of at least two genes coding for the replicative and structural proteins. Such a procedure of PCR permits the detection of Sindbis viruses of different geographic origin with changes in their primary structure and allows the differentiation between Sindbis viruses and Western equine encephalomyelitis viruses within the serological complex.

Encephalitis Virus, Western Equine↗
PubMedDate not supplied

[Similarities and differences between western equine encephalomyelitis viruses with respect to genes for nonstructural protein NSP2 and structural proteins C and E2].

Genetic relationships of geographical isolates of the members of WEE virus serocomplex (McMillan, Fort Morgan, Highlands J, and Y62-33) were assessed by the polymerase chain reaction (PCR) and restriction analysis of the PCR products. Oligonucleotide primers (21 nucleotides in length) were chosen for NSP2, nucleocapsid C, and E2-E1 protein genes based on the known primary structure of the McMillan 16310-5614 genome (L. Uryvayev et al., 1994, 1995). These primers were shown to differentiate well the WEE and SV-like strains of the serocomplex. Y62-33 virus (Udmurtia, Russia) was identical to McMillan strain in three studied regions of NSP2, C, and E2-E1 genes. NSP2 gene could be detected in all the studied geographical isolates and was characterized by the same restriction patterns as endonucleases; it appeared to be the most conservative. The structural genes were less conservative. Fort Morgan virus (Colorado, USA) genome reliably differed from McMillan virus (California, USA) and was negative in PCR with primers to C and E2 gene regions. Highlands J genome (Florida, USA) was positive in PCR with the primers to E2-E1 gene regions but differed from McMillan strain by the nucleocapsid gene. An additional comparative PCR analysis of the C-E2 region in the McMillan and Highlands J genomes showed some, but not complete identity. The origin of these two viruses might be due to the selection of different forms of recombinant viruses. A good correlation of structural genes in PCR and the infectivity neutralization test was noted with the primers and polyclonal antibodies to the closely related strains. High specificity of PCR permits a more accurate detection of the virus origin and relationships.

Animals↗
PubMedDate not supplied

[Recombination of alpha-viruses during mixed infection in cultured cells. Formation of hybrid forms of RNA of Venezuelan equine encephalomyelitis virus and Karelian fever virus in the region of genes for nucleocapsid and envelope proteins].

A recombination of the genomes of VEE and KF viruses, two alphaviruses of different serotypes, takes place in mixed infection of chick embryo fibroblasts and Vero cells with vaccine strain VEE-230 and KF-9298 strain. This recombination resulted in the production of recombinant virions with altered antigenic properties. Polymerase chain reaction (PCR) rapidly and effectively detected the hybrid sites of the genome in recombinant viruses. Short nucleotide sequences (approximately 20 n. p.) of a known primary structure in the RNA genomes, specifically reacting with the complementary PCR primers, were chosen as genetic markers. These data are the first experimental validation of the probable recombinant formation of alphaviruses in nature. They are in good agreement with findings of the recombinant structure of Western equine encephalomyelitis virus genome.

Alphavirus↗
PubMedDate not supplied

[Comparative analysis of primary structure of nucleocapsid protein from Western equine encephalomyelitis virus and other alphaviruses].

Part of WEE virus (strain 16310-5614) genome coding for the nucleocapsid (C) protein was cloned and sequenced in two independent clones. The C gene of WEE virus is composed of 77 nucleotides, both for the BFS and 16310 strains, and is 48, 24, 33, 15, 3, and 3 nucleotides shorter than that of Venezuelan equine encephalomyelitis (VEE), Semliki Forest, Ross River, Sindbis, O'Nyong-Nyong, and Eastern equine encephalomyelitis (EEE) viruses, respectively. It contains 16 nucleotide changes in comparison with the BFS-1703 strain, four of which are significant: Ser57(BFS)-->Ala(16310), Gly63-->Cys, Lys74-->Glu, Gly97-->Trp. Amino acid composition, charges, hydropathic profiles, and location of potential functional sites in C proteins of the heretofore studied alphaviruses have been compared. High positively charged N-domain of the nucleocapsid is the most variable in all alphaviruses and is characterized by an irregular secondary structure due to high Pro content (25.5%). Positively charged Lys (10.8% of total) and Arg (6.9% of total) are presented 18 and 11 times, respectively, in the N-domain of WEE virus (16310) protein, and clusters thereof possibly form the initial sites for interaction with RNA. Only Sindbis virus (HRSP and Ock) nucleocapsids do not contain Cys, while others do contain several residues. This part of C protein includes overlapping nuclear transport signals predicted for several cellular proteins and repeated 4, 7, and 2 times in WEE, EEE, and Sindbis viruses, respectively. There is a highly conservative region (96-113 as residues) in the C protein structure of all studied alphaviruses, which potentially binds to a large ribosomal subunit as it was shown for Sindbis virus by Wengler et al. (1992), and a consensus motif K/R95-P-X-K/R-X-R-M could be a main part of the nucleoprotein ribosome binding site. The W186HHGAVQ (WEE virus) is absolutely conservative for all alphaviruses and with the invariant Asn222 could have a common function, including C protein lateral interaction (Choi et al., 1991). The origination of WEE virus C protein from EEE virus is confirmed by very high (92.7%) similarity of this protein's C domain in the WEE/EEE pair and low (64.8%) in the WEE/Sindbis pair. Determination of C gene and protein type in the Sindbis/WEE virus serocomplex might be useful in the differential identification of this virus group.

Alphavirus↗
PubMedDate not supplied

[Comparative analysis of expression of genes for 2',5'-oligoadenylate synthetase and mRNA for dsRNA-protein kinase in human fibroblasts infected with the Sindbis alphavirus and induced by alpha-interferon].

Expression of 2,5-OAS and ds-protein kinase (ds-PK) in human fibroblast culture following treatment with alpha-IF in a dose of 1000 U or challenge with Karelian fever virus (KFV) (5 PFU/cell, 4 h.p.i.) was compared. A highly sensitive and rapid method, coupled RT-PCR, was used to detect mRNA transcription levels. Alpha-IF had an expressed stimulating effect on 2,5-OAS mRNA level, whereas the virus markedly inhibited the synthesis of ds-PK mRNA.

2',5'-Oligoadenylate Synthetase↗