Cripavirus (taxid:144051)

VIRION

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Non enveloped, pseudo T=3 icosahedral capsid, about 30 nm in diameter.
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GENOME

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Monopartite, linear ssRNA(+) genome of 8.5-10.2 kb, with a VPg bound at the 5'-terminus and a 3'-polyA tract. Contains two non-overlapping open reading frames, ORF1 and ORF2, which respectively encode the nonstructural and structural proteins.

GENE EXPRESSION

The virion RNA is infectious and serves as both genome and mRNA. The genome ORF1 and ORF2 encode two polyproteins, the first of which contains the non-structural proteins involved in replication, while the second, contains four capsid proteins. Each ORF is preceded by an internal ribosome entry site (IRES) located at the 5' end and at the intergenic region (IGR) between the two ORFs. Tha IGR IRES allows translation of ORF2 at a non-AUG codon.
Ribosomal skipping may also be used to express viral protein 1A from ORF1 of cricket paralysis virus.

ENZYMES

REPLICATION

  1. Virus penetrates into the cell.
  2. Uncoating, and release of the viral genomic RNA into the cytoplasm.
  3. Synthesis and proteolytic cleavage of the replicase polyprotein RNA1.
  4. Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
  5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
  6. Expression of the RNA2 polyprotein (structural proteins).
  7. virus release (or cell-cell spread of viral RNAs?).

Host-virus interaction

Host gene expression shutoff by virus

CrPV infection results in host translation shutoff concomitant with an increase in viral protein synthesis via CrPV internal ribosome entry sites (IRES). Host translation shutoff involves the dissociation of eIF4G and eIF4E .

Suppression of RNA silencing

Drosophila C virus protein DCV-1A and Cricket paralysis virus protein CrPV-1A function as suppressor of RNA silencing .

Matching UniProtKB/Swiss-Prot entries

(all links/actions below point to uniprot.org website)

3 entries grouped by strain

2 entries

Cricket paralysis virus (isolate Teleogryllus commodus/Australia/CrPVVIC/1968) (CrPV) reference strain

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POLS_CRPVC Structural polyprotein [Cleaved into: Capsid protein 1 (CP1); Capsid protein 4 (CP4); Capsid protein ...
POLN_CRPVC Replicase polyprotein [Cleaved into: Protein 1A (CrPV-1A); Protein 2A; Protein 2B; Protein 2C; ...

1 entry

Drosophila C virus (strain EB) (DCV)

POLN_DCVEB Replicase polyprotein [Cleaved into: Protein 1A; Protein 2A; Protein 2B; Protein 2C; Protein 3A; ...