Cypovirus (taxid:10981)



Non enveloped, icosahedral virion with a T=2* icosahedral symmetry, about 65 nm in diameter. Pentameric turrets sit on the outside of the capsid. The capsid is composed of only a single shell of protein.



Segmented dsRNA linear genome: 10 segments encode for 10-12 proteins. Segments size range from 1 to 4.2 kb. Genome total size is about 25 kb.


The dsRNA genome is never completely uncoated, to prevent activation of antiviral state by the cell in response to dsRNA. The viral polymerase lambda3 synthesizes a capped and non-polyadenylated monocistronic mRNA from each dsRNA segment. These capped mRNAs are translocated to the cell cytoplasm where they are translated.
NSP5 ORF produces two proteins by ribosomal skipping.




  1. Attachment to host receptors probably mediates endocytosis of virus into host cell.
  2. Particles are partially uncoated in endolysosomes, but not entirely, and penetrate in the cytoplasm.
  3. Early transcription of the dsRNA genome by viral polymerase occurs inside this sub-viral particle (naked core), so that dsRNA is never exposed to the cytoplasm.
  4. Full-length plus-strand transcripts from each of the dsRNA segments are synthesized. These plus-strand transcripts are used as templates for translation.
  5. Viral proteins and genomic RNAs aggregates in cytoplasmic viral factories.
  6. (+)RNAs are encapsidated in a sub-viral particle, in which they are transcribed to give RNA (-) molecules with which they become base-paired to produce dsRNA genomes.
  7. The capsid is assembled on the sub-viral particle.
  8. Mature virions are released presumably following cell death and associated breakdown of host plasma membrane.

Matching UniProtKB/Swiss-Prot entries

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15 entries grouped by strain

10 entries

Lymantria dispar cypovirus 1 (isolate Rao) (LdCPV-1) reference strain

VP6_LDCPR Microtubule-associated protein VP6
VP4_LDCPR Outer capsid protein VP4 [Includes: mRNA guanylyltransferase (EC; mRNA ...
RDRP_LDCPR RNA-directed RNA polymerase VP2 (EC
CAPSD_LDCPR Major capsid protein VP1
PYHD_LDCPR Polyhedrin
NS5_LDCPR Non-structural protein 5 (NS5)
NS3_LDCPR Non-structural protein 3 (NS3)
VP5_LDCPR Putative structural protein VP5
NS1_LDCPR Non-structural protein 1 (NS1)
VP3_LDCPR Putative structural protein VP3

2 entries

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV)

PYHD_CPVBM Polyhedrin (C-polyhedrin)
CAPSD_CPVBM Capsid protein VP1

1 entry

Choristoneura fumiferana cypovirus (CfCPV) (Choristoneura fumiferana cytoplasmic polyhedrosis virus)

PYHD_CPVCS Polyhedrin (C-polyhedrin)

1 entry

Euxoa scandens cypovirus (EsCPV) (Euxoa scandens cytoplasmic polyhedrosis virus)

PYHD_CPVES Polyhedrin (C-polyhedrin)

1 entry

Orgyia pseudotsugata cypovirus (OpCPV) (Orgyia pseudotsugata cytoplasmic polyhedrosis virus)

PYHD_CPVOP Polyhedrin (C-polyhedrin)