Rapid sequence modification in the highly polymorphic region (HPR) of the hemagglutinin gene of the infectious salmon anaemia virus (ISAV) suggests intra‐segmental template switching recombination

2020 ◽  
Vol 43 (12) ◽  
pp. 1483-1496
Author(s):  
Matías Cárdenas ◽  
Claudia Galleguillos ◽  
Karina Acevedo ◽  
Catarina Ananias ◽  
Javiera Alarcón ◽  
...  
Keyword(s):  
Template Switching ◽  
Infectious Salmon Anaemia Virus ◽  
Polymorphic Region ◽  
Rapid Sequence ◽  
Hemagglutinin Gene ◽  
Infectious Salmon Anaemia ◽  
Sequence Modification

scholarly journals Deletions in the highly polymorphic region (HPR) of infectious salmon anaemia virus HPR0 haemagglutinin–esterase enhance viral fusion and influence the interaction with the fusion protein

2014 ◽  
Vol 95 (5) ◽  
pp. 1015-1024 ◽  
Author(s):  
Mickael Fourrier ◽  
Katherine Lester ◽  
Even Thoen ◽  
Aase Mikalsen ◽  
Øystein Evensen ◽  
...  
Keyword(s):  
Firefly Luciferase ◽  
Infectious Salmon Anaemia Virus ◽  
Viral Fusion ◽  
Polymorphic Region ◽  
Physical Separation ◽  
F Protein ◽  
Strength Of Interaction ◽  
Membrane Region ◽  
Infectious Salmon Anaemia

Since the discovery of a non-virulent infectious salmon anaemia virus (ISAV) HPR0 variant, many studies have speculated on the functional role of deletions within the highly polymorphic region (HPR) of genomic segment 6, which codes for the haemagglutinin–esterase (HE) protein. To address this issue, mutant HE proteins with deletions in their HPR were generated from the Scottish HPR0 template (NWM10) and fusion-inducing activity was measured using lipid (octadecyl rhodamine B) and content mixing assays (firefly luciferase). Segment six HPR was found to have a strong influence on ISAV fusion, and deletions in this near-membrane region predominantly increased the fusion-inducing ability of the resulting HE proteins. The position and length of the HPR deletions were not significant factors, suggesting that they may affect fusion non-specifically. In comparison, the amino acid composition of the associated fusion (F) protein was a more crucial criterion. Antibody co-patching and confocal fluorescence demonstrated that the HE and F proteins were highly co-localized, forming defined clusters on the cell surface post-transfection. The binding of erythrocyte ghosts on the attachment protein caused a reduction in the percentage of co-localization, suggesting that ISAV fusion might be triggered through physical separation of the F and HE proteins. In this process, HPR deletion appeared to modulate and reduce the strength of interaction between the two glycoproteins, causing more F protein to be released and activated. This work provides a first insight into the mechanism of virulence acquisition through HPR deletion, with fusion enhancement acting as a major contributing factor.

scholarly journals Antigenic variation among isolates of infectious salmon anaemia virus correlates with genetic variation of the viral haemagglutinin gene

2001 ◽  
Vol 82 (12) ◽  
pp. 2869-2879 ◽  
Author(s):  
Frederick S. B. Kibenge ◽  
Molly J. T. Kibenge ◽  
Patricia K. McKenna ◽  
Paul Stothard ◽  
Rebecca Marshall ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Antigenic Variation ◽  
Comparative Sequence Analysis ◽  
Infectious Salmon Anaemia Virus ◽  
Marine Aquaculture ◽  
Sequence Identity ◽  
Ha Gene ◽  
Infectious Salmon Anaemia

Infectious salmon anaemia virus (ISAV), an orthomyxovirus-like virus, is an important fish pathogen in marine aquaculture. Virus neutralization of 24 ISAV isolates in the TO cell line using rabbit antisera to the whole virus and comparative sequence analysis of their haemagglutinin (HA) genes have allowed elaboration on the variation of ISAV isolates. The 24 viruses were neutralized to varying degrees, revealing two major antigenic groups, one American and one European. Sequence analysis of the HA gene also revealed two groups of viruses (genotypes) that correlated with the antigenic groupings. The two HA subtypes had nucleotide sequence identity of only ⩽79·4% and amino acid sequence identity of ⩽84·5% whereas, within each subtype, the sequence identities were 90·7% or higher. This grouping was also evident upon phylogenetic analysis, which revealed two distinct phylogenetic families. Between the two groups, the amino acid sequence was most variable in the C-terminal region and included deletions of 4–16 amino acids in all isolates relative to ISAV isolate RPC/NB-980 280-2. In order to view the relationships among these sequences and the HA sequences of the established orthomyxoviruses, a second phylogenetic tree was constructed which showed the ISAV sequences to be more closely related to sequences from Influenzavirus A and Influenzavirus B than to sequences from Influenzavirus C and Thogotovirus. The extensive deletions in the gene of European ISAV isolates lead us to speculate that the archetypal ISAV was probably of Canadian origin.

scholarly journals Dual Mutation Events in the Haemagglutinin-Esterase and Fusion Protein from an Infectious Salmon Anaemia Virus HPR0 Genotype Promote Viral Fusion and Activation by an Ubiquitous Host Protease

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0142020 ◽  
Author(s):  
Mickael Fourrier ◽  
Katherine Lester ◽  
Turhan Markussen ◽  
Knut Falk ◽  
Christopher J. Secombes ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Infectious Salmon Anaemia Virus ◽  
Viral Fusion ◽  
Infectious Salmon Anaemia

Transcriptional regulation of gene expression of infectious salmon anaemia virus segment 7

2014 ◽  
Vol 190 ◽  
pp. 69-74 ◽  
Author(s):  
Rimatulhana B. Ramly ◽  
Christel M. Olsen ◽  
Stine Braaen ◽  
Elisabeth F. Hansen ◽  
Espen Rimstad
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Regulation Of Gene Expression ◽  
Infectious Salmon Anaemia Virus ◽  
Infectious Salmon Anaemia

scholarly journals Low virulent infectious salmon anaemia virus (ISAV-HPR0) is prevalent and geographically structured in Norwegian salmon farming

2012 ◽  
Vol 101 (3) ◽  
pp. 197-206 ◽  
Author(s):  
TM Lyngstad ◽  
AB Kristoffersen ◽  
MJ Hjortaas ◽  
M Devold ◽  
V Aspehaug ◽  
...  
Keyword(s):  
Infectious Salmon Anaemia Virus ◽  
Salmon Farming ◽  
Infectious Salmon Anaemia
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