Orthoreovirus

VIRION

Non enveloped, icosahedral virion with a double capsid structure, about 80 nm in diameter. Pentameric turrets sit on the outside of the innermost capsid. The outer capsid has a T=13 icosahedral symmetry, the inner capsid a T=2* icosahedral symmetry.
Virion maturation schemes

GENOME

Segmented dsRNA linear genome. Contains 10 segments: L1, L2, L3, M1, M2, M3, S1, S2, S3, S4, coding for 12-13 proteins. Segments size range from 1,189 to 3,916nt (MRV-3De). Genome total size is 23.5 Kb (MRV-3De). MuNSC and S.1s are produced by leaky scanning of mRNA M3 and S1 respectively.

GENE EXPRESSION

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.

REPLICATION

CYTOPLASMIC

  1. Attachement to host receptors mediates clathrin-mediated 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.

Host-virus interaction

Apoptosis modulation

Mammalian reovirus mediates host cell apoptosis through the activation of death receptors, including TRAIL, TNFR and Fas . Activation of these death receptors induces the activation downstream caspases (caspase-3).

Avian orthoreovirus induces host cell apoptosis probably through upregulation of p53 (activation of DNA-damage signalling) by viral sigmaC protein .

Autophagy modulation

Avian orthoreovirus also seems to induces autophagy .

Innate immune response inhibition

Mammalian orthoreoreovirus σ3 protein binds to dsRNA and inhibits the PRK-mediated antiviral response of the host cell .
Mammalian orthoreovirus &mu2; protein from strain Lang (T1L) inhibits IFN-beta-induced reporter gene expression .

Avian orthoreovirus σA protein binds to dsRNA and inhibits the PRK-mediated antiviral response of the host cell .

Cell-cycle modulation

Human and avian reovirus induce G2/M cell cycle arrest .

Matching UniProtKB/Swiss-Prot entries

34 entries grouped by protein (browse by keywords)

All proteins are shown (view only 32 complete proteome entries)

3 entries

Inner capsid protein lambda-1 (Lambda1) (EC 3.6.4.13) (ATP-dependent DNA helicase lambda-1) (Lambda1(Hel))

Select_allDeselect_all
LMBD1_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
LMBD1_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
LMBD1_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Outer capsid protein lambda-2 (Lambda2) (Lambda2(Cap))

Select_allDeselect_all
LMBD2_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
LMBD2_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
LMBD2_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Outer capsid protein mu-1 (Mu1)

Select_allDeselect_all
MU1_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
MU1_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
MU1_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Microtubule-associated protein mu-2 (Mu2)

Select_allDeselect_all
MU2_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
MU2_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
MU2_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Protein mu-NS (MuNS)

Select_allDeselect_all
MUNS_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
MUNS_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
MUNS_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

RNA-directed RNA polymerase lambda-3 (Lambda3) (EC 2.7.7.48) (Lambda3(Pol))

Select_allDeselect_all
RDRP_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
RDRP_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
RDRP_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Protein sigma-1-small (Sigma1s) (Sigma-s) (Sigma1NS) (Sigma1bNS) (p14)

Select_allDeselect_all
SIG1S_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
SIG1S_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
SIG1S_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

1 entry

Sigma-C capsid protein (Sigma-3 protein)

SIGC_ARVS1
Avian reovirus (strain S1133) (ARV)

3 entries

Outer capsid protein sigma-1 (Sigma1) (Cell attachment protein) (Hemagglutinin)

Select_allDeselect_all
SIGM1_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
SIGM1_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
SIGM1_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Inner capsid protein sigma-2 (Sigma2)

Select_allDeselect_all
SIGM2_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
SIGM2_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
SIGM2_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Outer capsid protein sigma-3 (Sigma3)

Select_allDeselect_all
SIGM3_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
SIGM3_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
SIGM3_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)

3 entries

Protein sigma-NS (SigmaNS)

Select_allDeselect_all
SIGNS_REOVL
Reovirus type 1 (strain Lang) (T1L) (Mammalian orthoreovirus 1) reference strain
SIGNS_REOVD
Reovirus type 3 (strain Dearing) (T3D) (Mammalian orthoreovirus 3)
SIGNS_REOVJ
Reovirus type 2 (strain D5/Jones) (T2J) (Mammalian orthoreovirus 2)