Mengovirus, also known as Columbia SK virus, mouse Elberfield virus, and Encephalomyocarditis virus (EMCV), belongs to the genus ''
Cardiovirus'' which is a member of the ''
Picornaviridae
Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 nm ...
''. Its genome is a single stranded
positive-sense
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, ...
RNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
molecule, making the Mengoviruses a
class IV virus under the
Baltimore classification
Baltimore classification is a system used to classify viruses based on their manner of messenger RNA (mRNA) synthesis. By organizing viruses based on their manner of mRNA production, it is possible to study viruses that behave similarly as a disti ...
system. The genome is approximately 8400nt in length, and has 5’ VG protein (Virus genome protein) and a 3’ polyadenine tail. Mengovirus was isolated by George W. A. Dick in 1948, in the Mengo district of Entebbe in Uganda, from a captive rhesus monkey that had developed hind limb paralysis.
Structure
Mengovirus is a non-enveloped virus which has a nucleocapsid made up of 12 subunits. The
virion
A virion (plural, ''viria'' or ''virions'') is an inert virus particle capable of invading a Cell (biology), cell. Upon entering the cell, the virion disassembles and the genetic material from the virus takes control of the cell infrastructure, t ...
is 30 nm in diameter and displays icosahedral 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 the host
ribosomes
Ribosomes () are macromolecular machines, found within all cells, that perform biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA molecules to fo ...
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
dipyridamole
Dipyridamole, sold under the brand name Persantine among others, is an antiplatelet drug of the nucleoside transport inhibitor and PDE3 inhibitor class that inhibits blood clot formation when given chronically and causes blood vessel dilatio ...
has been shown to inhibit its replication.
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
Nuclear may refer to:
Physics
Relating to the nucleus of the atom:
*Nuclear engineering
*Nuclear physics
*Nuclear power
*Nuclear reactor
*Nuclear weapon
*Nuclear medicine
*Radiation therapy
*Nuclear warfare
Mathematics
*Nuclear space
*Nuclear ...
using the 5’ un-translated region.
References
Further reading
* Rueckert RR (1990) Picornavirus and their multiplication. In: Fields BN, Knipe DM (eds) Virology, 2nd edn. Raven Press, New York, pp 507–548.
EncephalomyocarditisvirusICTVdB Index of Viruses, Version 28, June, 2002. Retrieved on 2007-07-15.
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{{Taxonbar, from=Q6817023
Cardioviruses