Macronovirus

Satellite virus: infection requires host cell to be co-infected with Macrobrachium rosenbergii nodavirus (MrNV)

VIRION

Non-enveloped, spherical, capsid of about 15 nm with icosahedral symmetry. The virion is constructed from two capsid proteins CP-17 and CP-16.

GENOME

Monopartite, linear, ssRNA(+) genome of 0,8 kb in size. 3' terminus has a short poly (A) tract. Encodes two capsid proteins CP-17 and CP-16.

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA.

REPLICATION

CYTOPLASMIC

  1. Attachement to host receptors mediates entry into the host cell.
  2. Uncoating, and release of the viral genomic RNA into the cytoplasm.
  3. Viral RNA is translated in a polyprotein to produce replication proteins.
  4. Replication occurs in viral factories made of membrane vesicles derived from the ER. 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 capsid proteins.
  7. Assembly of new virus particles.
  8. Virus release.