Mengovirus

Mengovirus
Virus classification
Group: Group IV ((+)ssRNA)
Family: Picornaviridae
Genus: Cardiovirus
Species: Encephalomyocarditis virus
Subtype

Mengovirus

Mengovirus, also known as Columbia SK virus, mouse Elberfield virus and Encephalomyocarditisvirus (EMCV), belongs to the genus Cardiovirus which is a member of the Picornaviridae. Its genome is a single stranded positive-sense RNA molecule, making the Mengoviruses a class IV virus under the Baltimore classification system. The genome is approximately 8400nt in length, and has 5’ VG protein (Virus genome protein) and a 3’ polyadenine tail.

Structure

The Mengovirus is a non-enveloped virus which has a nucleocapsid made up of 12 subunits. The virion is 30 nm in diameter and displays icosohedral symmetry.

Gene Expression and Genome Replication

Once inside a host cell, the Mengovirus genome acts as a piece of mRNA, and is directly translated by host ribosomes in the cytoplasm. There is a large un-translated region at the 5’ end of the RNA that has a ribosome binding site, removing the need of a cap. A single polypeptide is made, and is cleaved into individual proteins by viral proteases. The genome is divided into three parts: P1, P2 and P3. P1 encodes the virus capsid proteins, P2 and P3 encode genes required for genome replication to occur. For replication to occur an intermediate double stranded RNA molecule is made to be used as a template for the production of positive sense genomes.

Infection

Mengovirus is infectious to vertebrate animals, and has been isolated from mice and other rodents. It can also cause acute fever in humans. There is no specific treatment for a Mengovirus infection; although Persantine has been shown to inhibit its replication.[1] The illness is not severe enough to require vaccination. The Mengovirus is able to suppress the host’s immune response by reducing the expression of Nuclear Factor kappa B using the 5’ un-translated region.

References

  1. ↑ http://jvi.asm.org/cgi/content/full/79/17/11062?view=long&pmid=16103157

Further reading

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