Cripavirus

Cripavirus is a genus of viruses in the order Picornavirales, in the family Dicistroviridae. Invertebrates serve as natural hosts. There are currently nine species in this genus including the type species Cricket paralysis virus. Diseases associated with this genus include: DCV: increased reproductive potential; extremely pathogenic when injected with high associated mortality; CrPV: paralysis and death.[1][2] These viruses can produce proteins directly from their RNA genome upon entering a cell; and therefore, does not require an RNA polymerase packaged in with it, as this may be produced from the genome after entering the cell.[3] The name of the cripavirus family originates from its most famous member the Cricket Paralysis Virus.[3] Which was made famous by its rather unusual IRES (Internal Ribosome Entry Site): the Cripavirus IRES. The Cripavirus IRES is an RNA element that allows the virus to bind the ribosome and translate without a need for any initiation factors[4] – as initiation is the most regulated step of translation this allows the virus to avoid many mechanisms to inhibit viral activity.

Cripavirus
Virus classification
Group:
Group IV ((+)ssRNA)
Order:
Picornavirales
Family:
Dicistroviridae
Genus:
Cripavirus
Type Species

Taxonomy

Group: ssRNA(+)

[2]

Structure

Viruses in Cripavirus are non-enveloped, have capsids of 12 capsomers, and have icosahedral geometries with T=pseudo3 symmetry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 8.5–10.2kb in length, and has a VPg (genome linked viral protein) on the 5' end. The 5' end also has a series of C's near it, while the 3' end has a series of A's near it. The genome has 2 open reading frames.[1]

GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
CripavirusIcosahedralPseudo T=3Non-envelopedLinearMonopartite

Life cycle

Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method of transcription. Translation takes place by viral initiation, and ribosomal skipping. Invertebrates serve as the natural host. Transmission routes are contamination.[1]

GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
CripavirusInvertebratesNoneCell receptor endocytosisBuddingCytoplasmCytoplasmFood

References
  1. "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
  3. International Committee on the Taxonomy of Viruses Archived 1 December 2008 at the Wayback Machine
  4. "Structure and Function of Regulatory RNA Elements", Biochimica et Biophysica Acta, 1789: 542–557, 2009, doi:10.1016/j.bbagrm.2009.07.005, PMID 19632368
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