Dicistroviridae

VIRION

Non enveloped, T=pseudo3 icosahedral capsid, about 30 nm in diameter.

Virusworld image of CrPV-1

GENOME

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 three (or more) capsid proteins. Each ORF is preceded by one internal ribosome entry site located at the 5’ end and in the middle of the mRNA.
Ribosomal skipping may also be used to express viral protein 1A from ORF1 of cricket paralysis virus.

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. 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

6 entries grouped by strain (browse by keywords)

All proteins are shown (view only 5 complete proteome entries)

3 entries

Acute bee paralysis virus (strain Rothamsted) (ABPV) reference strain

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POG_ABPVRPutative protein pog (ORFx protein)
POLN_ABPVRReplicase polyprotein (EC 2.7.7.48) (EC 3.4.22.-)
POLS_ABPVRStructural polyprotein

2 entries

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

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POLN_CRPVCReplicase polyprotein
POLS_CRPVCStructural polyprotein

1 entry

Drosophila C virus (strain EB) (DCV)


POLN_DCVEBReplicase polyprotein