Partial Nucleotide and Amino Acid Sequences of the Envelope and the Envelope/Nonstructural Protein-1 Gene Junction of Four Dengue-2 Virus Strains Isolated during the 1981 Cuban Epidemic

1995 ◽  
Vol 52 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Maria G. Guzman ◽  
Carlos Sariol ◽  
Vincent Deubel ◽  
Miguel Marrero ◽  
Gustavo Kouri ◽  
...  
2020 ◽  
Vol 94 (20) ◽  
Author(s):  
Derek L. Carbaugh ◽  
Shuntai Zhou ◽  
Wes Sanders ◽  
Nathaniel J. Moorman ◽  
Ronald Swanstrom ◽  
...  

ABSTRACT Recent Zika virus (ZIKV) outbreaks and unexpected clinical manifestations of ZIKV infection have prompted an increase in ZIKV-related research. Here, we identify two strain-specific determinants of ZIKV virulence in mice. We found that strain H/PF/2013 caused 100% lethality in Ifnar1−/− mice, whereas PRVABC59 caused no lethality; both strains caused 100% lethality in Ifnar1−/− Ifngr1−/− double-knockout (DKO) mice. Deep sequencing revealed a high-frequency variant in PRVABC59 not present in H/PF/2013: a G-to-T change at nucleotide 1965 producing a Val-to-Leu substitution at position 330 of the viral envelope (E) protein. We show that the V330 variant is lethal on both virus strain backgrounds, whereas the L330 variant is attenuating only on the PRVABC59 background. These results identify a balanced polymorphism in the E protein that is sufficient to attenuate the PRVABC59 strain but not H/PF/2013. The consensus sequences of H/PF/2013 and PRVABC59 differ by 3 amino acids, but these were not responsible for the difference in virulence between the two strains. H/PF/2013 and PRVABC59 differ by an additional 31 noncoding or silent nucleotide changes. We made a panel of chimeric viruses with identical amino acid sequences but nucleotide sequences derived from H/PF/2013 or PRVABC59. We found that 6 nucleotide differences in the 3′ quarter of the H/PF/2013 genome were sufficient to confer virulence in Ifnar1−/− mice. Altogether, our work identifies a large and previously unreported difference in virulence between two commonly used ZIKV strains, in two widely used mouse models of ZIKV pathogenesis (Ifnar1−/− and Ifnar1−/− Ifngr1−/− DKO mice). IMPORTANCE Contemporary ZIKV strains are closely related and often used interchangeably in laboratory research. Here, we identify two strain-specific determinants of ZIKV virulence that are evident in only Ifnar1−/− mice but not Ifnar1−/− Ifngr1−/− DKO mice. These results identify a balanced polymorphism in the E protein that is sufficient to attenuate the PRVABC59 strain but not H/PF/2013. We further identify a second virulence determinant in the H/PF/2013 strain, which is driven by the viral nucleotide sequence but not the amino acid sequence. Altogether, our work identifies a large and previously unreported difference in virulence between two commonly used ZIKV strains, in two widely used mouse models of ZIKV pathogenesis. Our results highlight that even very closely related virus strains can produce significantly different pathogenic phenotypes in common laboratory models.


2020 ◽  
Vol 94 (8) ◽  
Author(s):  
Xiang Liu ◽  
Margit Mutso ◽  
Liubov Cherkashchenko ◽  
Eva Zusinaite ◽  
Lara J. Herrero ◽  
...  

ABSTRACT Ross River virus (RRV) belongs to the genus Alphavirus and is prevalent in Australia. RRV infection can cause arthritic symptoms in patients and may include rash, fever, arthralgia, and myalgia. Type I interferons (IFN) are the primary antiviral cytokines and trigger activation of the host innate immune system to suppress the replication of invading viruses. Alphaviruses are able to subvert the type I IFN system, but the mechanisms used are ill defined. In this study, seven RRV field strains were analyzed for induction of and sensitivity to type I IFN. The sensitivities of these strains to human IFN-β varied significantly and were highest for the RRV 2548 strain. Compared to prototype laboratory strain RRV-T48, RRV 2548 also induced higher type I IFN levels both in vitro and in vivo and caused milder disease. To identify the determinants involved in type I IFN modulation, the region encoding the nonstructural proteins (nsPs) of RRV 2548 was sequenced, and 42 amino acid differences from RRV-T48 were identified. Using fragment swapping and site-directed mutagenesis, we discovered that substitutions E402A and R522Q in nsP1 as well as Q619R in nsP2 were responsible for increased sensitivity of RRV 2548 to type I IFN. In contrast, substitutions A31T, N219T, S580L, and Q619R in nsP2 led to induction of higher levels of type I IFN. With exception of E402A, all these variations are common for naturally occurring RRV strains. However, they are different from all known determinants of type I IFN modulation reported previously in nsPs of alphaviruses. IMPORTANCE By identifying natural Ross River virus (RRV) amino acid determinants for type I interferon (IFN) modulation, this study gives further insight into the mechanism of type I IFN modulation by alphaviruses. Here, the crucial role of type I IFN in the early stages of RRV disease pathogenesis is further demonstrated. This study also provides a comparison of the roles of different parts of the RRV nonstructural region in type I IFN modulation, highlighting the importance of nonstructural protein 1 (nsP1) and nsP2 in this process. Three substitutions in nsP1 and nsP2 were found to be independently associated with enhanced type I IFN sensitivity, and four independent substitutions in nsP2 were important in elevated type I IFN induction. Such evidence has clear implications for RRV immunobiology, persistence, and pathology. The identification of viral proteins that modulate type I IFN may also have importance for the pathogenesis of other alphaviruses.


2015 ◽  
Vol 59 (4) ◽  
pp. 463-466
Author(s):  
Małgorzata Kwaśnik ◽  
Ilona Marcelina Góra ◽  
Wojciech Rożek

Abstract The immunoreactivity of haemagglutinin (HA) polypeptides of equine influenza virus was compared among the strains isolated in Poland, using H3 monoclonal antibody. A stronger signal in immunoblot reaction was observed for A/equi/Pulawy/2008 HA polypeptides compared to A/equi/Pulawy/2006, despite the fact that both strains are phylogenetically closely related and belong to Florida clade 2 of American lineage. The strongest signal, observed in the case of A/equi/Pulawy/2008, seemed to be connected with the presence of G135, I213, E379, and/or V530 instead of R135, M213, G379, and I530 present in A/equi/Pulawy/2006 HA sequence. This implies that point mutations within amino acid sequences of HA polypeptides of equine influenza virus may change their immunoreactivity even when they are not located within five basic antigenic sites.


2018 ◽  
Vol 5 (3) ◽  
pp. 65-74
Author(s):  
K. V. Smirnova ◽  
N. B. Senyuta ◽  
I. V. Botezatu ◽  
T. E. Dushenkina ◽  
A. K. Lubenskaya ◽  
...  

Objective of the investigation was to study the infection of ethnic Tatars with the Epstein–Barr virus (EBV) and to analyze the genetic structure of the oncogene of the virus, the latent membrane protein 1 (LMP1), in the virus strains of Tatar origin. Materials and methods. The materials for the study were samples of boucle flushes of 60 students from the Kazan State Medical University who are ethnic Tatars (Tatars no less than in the 3rd generation). Amplified from DNA of boucle flushes the nucleotide sequences of the LMP1 samples translated into DNA amino acid sequences, have undergone classification based on the well-known and widely used in literature the R.H. Edwards et al. classification. Results. The analysis of nucleotide and deductive amino acid sequences of the 41 LMP1 amplicons revealed their homology with only three gene variants from the R.H. Edwards et al. classification (1999): 95.8/A (29.3 %; 12/41), Med– (14.6 %; 6/41) and China1 (7.3 %, 3/41). Such variants of LMP1 as Alaskan, Med+, Chinа2, China3 and NC, were not found. Among the LMP1 samples of Tatar origin in 20 cases (48.8 %), the composition of the mutations found did not allow them to be assigned to any of the oncogene variants listed above. Out of this number, in 7 (17.1 %) cases a mono group of LMP1 samples was found, differing not only from representatives of the Slavs, inhabitants of the European part of Russia, but also from other Kazan samples, and was designated as LMP1-TatK. The remaining 13 samples of LMP1 (31.7 %), not belonging to any of the known classifications, formed the group designated by us as an LMP1 group beside the classification (LMP1BC). Conclusion. Continuation of the study of the molecular-biological and functional properties of LMP1 in TatK and BC groups, which constitute 48.8 % of the number of gene samples studied, and an analysis of the peculiarities of the ethnic Tatar genotype, will probably help to clarify whether certain EBV strains influence morbidity and mortality in Tatar population with malignant neoplasms, which include EBVassociated cases.


2001 ◽  
Vol 75 (2) ◽  
pp. 910-920 ◽  
Author(s):  
Christopher L. Parks ◽  
Robert A. Lerch ◽  
Pramila Walpita ◽  
Hai-Ping Wang ◽  
Mohinder S. Sidhu ◽  
...  

ABSTRACT Protein-encoding nucleotide sequences of the N, P, M, F, H, and L genes were determined for a low-passage isolate of the Edmonston wild-type (wt) measles virus and five Edmonston-derived vaccine virus strains, including AIK-C, Moraten, Schwarz, Rubeovax, and Zagreb. Comparative analysis demonstrated a high degree of nucleotide sequence homology; vaccine viruses differed at most by 0.3% from the Edmonston wt strain. Deduced amino acid sequences predicted substitutions in all viral polypetides. Eight amino acid coding changes were common to all vaccine viruses; an additional two were conserved in all vaccine strains except Zagreb. Comparisons made between vaccine strains indicated that commercial vaccine lots of Moraten and Schwarz had identical coding regions and were closely related to Rubeovax, while AIK-C and Zagreb diverged from the Edmonston wt along slightly different paths. These comparisons also revealed amino acid coding substitutions in Moraten and Schwarz that were absent from the closely related reactogenic Rubeovax strain. All of the vaccine viruses contained amino acid coding changes in the core components of the virus-encoded transcription and replication apparatus. This observation, combined with identification of noncoding region nucleotide changes in potential cis-acting sequences of the vaccine strains (C. L. Parks, R. A. Lerch, P. Walpita, H.-P. Wang, M. S. Sidhu, and S. A. Udem, J. Virol. 75:921–933, 2001), suggest that modulation of transcription and replication plays an important role in attenuation.


1993 ◽  
Vol 69 (04) ◽  
pp. 351-360 ◽  
Author(s):  
Masahiro Murakawa ◽  
Takashi Okamura ◽  
Takumi Kamura ◽  
Tsunefumi Shibuya ◽  
Mine Harada ◽  
...  

SummaryThe partial amino acid sequences of fibrinogen Aα-chains from five mammalian species have been inferred by means of the polymerase chain reaction (PCR). From the genomic DNA of the rhesus monkey, pig, dog, mouse and Syrian hamster, the DNA fragments coding for α-C domains in the Aα-chains were amplified and sequenced. In all species examined, four cysteine residues were always conserved at the homologous positions. The carboxy- and amino-terminal portions of the α-C domains showed a considerable homology among the species. However, the sizes of the middle portions, which corresponded to the internal repeat structures, showed an apparent variability because of several insertions and/or deletions. In the rhesus monkey, pig, mouse and Syrian hamster, 13 amino acid tandem repeats fundamentally similar to those in humans and the rat were identified. In the dog, however, tandem repeats were found to consist of 18 amino acids, suggesting an independent multiplication of the canine repeats. The sites of the α-chain cross-linking acceptor and α2-plasmin inhibitor cross-linking donor were not always evolutionally conserved. The arginyl-glycyl-aspartic acid (RGD) sequence was not found in the amplified region of either the rhesus monkey or the pig. In the canine α-C domain, two RGD sequences were identified at the homologous positions to both rat and human RGD S. In the Syrian hamster, a single RGD sequence was found at the same position to that of the rat. Triplication of the RGD sequences was seen in the murine fibrinogen α-C domain around the homologous site to the rat RGDS sequence. These findings are of some interest from the point of view of structure-function and evolutionary relationships in the mammalian fibrinogen Aα-chains.


1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig Jackson

Bovine Factor X is eluted in two forms (X1and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglutamic acid residues have been shown to be identical in X1 and X2(H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by anion-exchange chromatography. The activation peptide (AP1) which eluted first was shown to be derived from Factor X1. while the activation peptiae (AP2) which eluted second was shown to be derived from X2 on the basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.M.J. is an Established Investigator of the American Heart Association).


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