Cucumovirus (taxid:12304)
VIRION

Non-enveloped, spherical virion about 29nm in diameter with T=3 icosahedral symmetry, composed of 180 coat proteins: 12 pentamers and 20 hexamers.
GENOME
Segmented, tripartite linear ssRNA(+) genome composed of RNA1, RNA2, RNA3. Each genomic segment has a 3' tRNA-like structure and a 5'cap.
GENE EXPRESSION
Genomic RNA serves as messenger RNAs. RNA1 and RNA2 encode respectively proteins 1a and 2a, both involved in genome replication and internal transcription of sgRNA4 from the minus-strand copy of RNA3. RNA3 and sgRNA4 are translated respectively into movement and capsid proteins. ORF2b encodes a viral suppressor of RNA silencing (VSR) and is expressed probably as a subgenomic RNA (sgRNA4A).
ENZYMES
REPLICATION
CYTOPLASMIC
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- Expression of protein 1a and 2a to produce replication proteins.
- Replication occurs in viral factories made of membrane vesicles derived from the ER (spherules). A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
- Subgenomic RNA4 is translated producing capsid proteins.
- Assembly of new virus particles.
- Viral movement protein triggers the formation of tubular structures that mediate virion cell-to-cell transfer via a tubule-guided mechanism.
Host-virus interaction
Suppression of RNA silencing
Cucumovirus protein 2b acts as a suppressor of RNA silencing
.
Matching UniProtKB/Swiss-Prot entries
(all links/actions below point to uniprot.org website)74 entries grouped by protein
9 entries
Replication protein 1a
3 entries
Suppressor of silencing 2b (Protein 2b)
29 entries
Capsid protein (CP) (Coat protein)
20 entries
Movement protein (MP) (Protein 3A)
13 entries