Alphavirus

VIRION

Enveloped, spherical, icosahedral, 65-70nm in diameter, capsid with a T=4 icosahedral symmetry made of 240 monomers. The envelope contains 80 spikes, each spike are trimer of E1/E2 proteins.

GENOME

Monopartite, linear, ssRNA(+) genome of 11-12 kb. The genome is capped and polyadenylated.

GENE EXPRESSION

The virion RNA is infectious and serves as both genome and viral messenger RNA. The whole genome is translated into a non-structural polyprotein which is processed by host and viral proteases. RdRp is expressed by suppression of termination at the end of 10% of nsP polyproteins. In late phase of infection, structural polyprotein is expressed through a subgenomic mRNA. The mRNA contains a Downstream Hairpin Loop (DLP)to avoid the translation shutoff induced by the host PKR in the late phase of infection. A truncated version of the structural polyprotein is produced by ribosomal frameshifting in the 6K region, the frameshift induces the translation of the TF protein .

REPLICATION

CYTOPLASMIC

  1. Attachement of the viral E glycoprotein to host receptors mediates clathrin-mediated endocytosis of virus into the host cell.
  2. Fusion of virus membrane with host endosomal membrane. RNA genome is released into the cytoplasm.
  3. The positive-sense genomic ssRNA is translated into a polyprotein, which is cleaved into non-structural proteins necessary for RNA synthesis (replication and transcription).
  4. Replication takes place in cytoplasmic viral factories at the surface of endosomes. 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 subgenomic RNA (sgRNA) gives rise to the structural proteins.
  7. Capsid assembly occurs in cytoplasm.
  8. The capsid is envelopped by budding at the plasma membrane where the virion exits the cell .

Host-virus interaction Chikungunya probably activates an autophagic process which promotes viral replication .

Host gene expression shutoff by virus

Togaviruses mediate host translation shutoff.
Alphaviruses induce strong PKR activation leading to leading to the almost complete phosphorylation of eIF2alpha and host translation arrest .

Alphaviruses perform host transcription shutoff by inhibiting host RNA polymerase II. Host RNA-pol II catalytic subunit is targeted for degradation as early as 4-6h p.i. .

Matching UniProtKB/Swiss-Prot entries

57 entries grouped by strain (browse by keywords)

All proteins are shown (view only 48 complete proteome entries)

2 entries

Semliki forest virus (SFV) reference strain

Select_allDeselect_all
POLS_SFV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_SFV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Chikungunya virus (strain S27-African prototype) (CHIKV) reference strain

Select_allDeselect_all
POLS_CHIKS Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_CHIKS Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Sindbis virus (SINV) reference strain

Select_allDeselect_all
POLS_SINDV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_SINDV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

1 entry

Semliki forest virus (SFV)

POLSF_SFV Frameshifted structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat ...

2 entries

Aura virus (AURAV)

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POLN_AURAV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_AURAV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Barmah forest virus (BFV)

Select_allDeselect_all
POLS_BFV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_BFV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

2 entries

Chikungunya virus (strain 37997) (CHIKV)

Select_allDeselect_all
POLS_CHIK3 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_CHIK3 Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Eastern equine encephalitis virus (strain Florida 91-469) (EEEV) (Eastern equine encephalomyelitis virus)

Select_allDeselect_all
POLN_EEEVF Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEEVF Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Eastern equine encephalitis virus (strain PE-0.0155) (EEEV) (Eastern equine encephalomyelitis virus)

Select_allDeselect_all
POLS_EEEV1 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_EEEV1 Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

2 entries

Eastern equine encephalitis virus (strain PE-3.0815) (EEEV) (Eastern equine encephalomyelitis virus)

Select_allDeselect_all
POLN_EEEV8 Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEEV8 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Getah virus (GETV)

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POLN_GETV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_GETV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Mayaro virus (strain Brazil) (MAYV)

Select_allDeselect_all
POLS_MAYAB Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_MAYAB Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

2 entries

O'nyong-nyong virus (strain Gulu) (ONNV)

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POLN_ONNVG Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...
POLS_ONNVG Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

O'nyong-nyong virus (strain Igbo Ora) (ONNV) (Igbo Ora virus)

Select_allDeselect_all
POLN_ONNVI Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...
POLS_ONNVI Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

O'nyong-nyong virus (strain SG650) (ONNV)

Select_allDeselect_all
POLN_ONNVS Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...
POLS_ONNVS Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Ross river virus (strain NB5092) (RRV)

Select_allDeselect_all
POLS_RRVN Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_RRVN Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Sagiyama virus (SAGV)

Select_allDeselect_all
POLS_SAGV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_SAGV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

2 entries

Salmon pancreas disease virus (SPDV)

Select_allDeselect_all
POLS_SPDV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.-) (Coat protein) (C); p62 ...
POLN_SPDV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Sindbis virus subtype Ockelbo (strain Edsbyn 82-5) (OCKV) (Ockelbo virus)

Select_allDeselect_all
POLS_SINDO Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...
POLN_SINDO Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

2 entries

Sleeping disease virus (SDV)

Select_allDeselect_all
POLS_SLDV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.-) (Coat protein) (C); p62 ...
POLN_SLDV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; mRNA-capping enzyme ...

2 entries

Venezuelan equine encephalitis virus (strain 3880) (VEEV)

Select_allDeselect_all
POLN_EEVV3 Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEVV3 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Venezuelan equine encephalitis virus (strain Mena II) (VEEV)

Select_allDeselect_all
POLN_EEVVM Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEVVM Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Venezuelan equine encephalitis virus (strain P676) (VEEV)

Select_allDeselect_all
POLN_EEVVP Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEVVP Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Venezuelan equine encephalitis virus (strain Trinidad donkey) (VEEV)

Select_allDeselect_all
POLN_EEVVT Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_EEVVT Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

2 entries

Western equine encephalitis virus (WEEV)

Select_allDeselect_all
POLN_WEEV Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...
POLS_WEEV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Chikungunya virus (strain Nagpur) (CHIKV)

POLS_CHIKN Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Eastern equine encephalitis virus (EEEV) (Eastern equine encephalomyelitis virus)

POLS_EEEV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Eastern equine encephalitis virus (strain va33[ten broeck]) (EEEV) (Eastern equine encephalomyelitis virus)

POLS_EEEV3 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Middelburg virus

POLS_MIDDV Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.-) (Coat protein) (C); p62 ...

1 entry

Ross river virus (strain T48) (RRV)

POLS_RRVT Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Venezuelan equine encephalitis virus (strain CPA201) (VEEV)

POLN_EEVVC Non-structural polyprotein (Polyprotein nsP1234) (P1234) [Cleaved into: P123; P123'; mRNA-capping ...

1 entry

Venezuelan equine encephalitis virus (strain Everglades Fe3-7c) (VEEV)

POLS_EEVVE Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...

1 entry

Venezuelan equine encephalitis virus (strain TC-83) (VEEV)

POLS_EEVV8 Structural polyprotein (p130) [Cleaved into: Capsid protein (EC 3.4.21.90) (Coat protein) (C); p62 ...