Enveloped, spherical, about 45-60 nm in diameter. The virion is comprised of an isometric core of 20-30 nm surrounded by a lipid-containing envelope. The RNA genome associates with the N protein to form the nucleocapsid.



Monopartite, linear, ssRNA(+) genome of 12-13kb in size, capped, and polyadenylated. The leader RNA (65-89 bp) at the 5' end of the genome is also present at the end of each subgenomic RNAs.


The virion RNA is infectious and serves as both genome and viral messenger RNA. ORF1b is translated by a ribosomal frameshifting. Polyproteins pp1a and pp1ab are processed into the viral polymerase (RdRp) and other non-structural proteins involved in RNA synthesis. Structural proteins are expressed as subgenomic RNAs. The mRNA2 is bicistronic.
Protein GP2 and 5a are produced by leaky scanning from the E and gp5 subgenomic mRNA respectively.



  1. Attachement to host receptors mediates clathrin-mediated endocytosis of the virus into the host cell.
  2. Fusion of virus membrane with the endosomal membrane. ssRNA(+) genome is released into the cytoplasm.
  3. Synthesis and proteolysis of replicase polyproteins.
  4. Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
  5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
  6. Synthesis of structural proteins encoded by subgenomic mRNAs.
  7. assembly and ESCRT-independent budding at the membranes of endoplasmic reticulum (ER), intermediate compartments, and/or Golgi complex.
  8. Release of new virions by exocytosis.

Host-virus interaction

Apoptosis modulation

The equine arteritis virus induces apoptosis via host caspases activation (caspase-8 and mitochondria-dependent caspase-9)

Matching UniProtKB/Swiss-Prot entries

9 entries grouped by strain (browse by keywords)

9 entries

Equine arteritis virus (strain Bucyrus) (EAV) reference strain

RPOA_EAVBU Replicase polyprotein 1ab (ORF1ab polyprotein) [Cleaved into: Nsp1 papain-like cysteine proteinase ...
NCAP_EAVBU Nucleoprotein (Nucleocapsid protein) (Protein N)
GP2B_EAVBU Glycoprotein 2b (Protein GP2b) (GP(S))
E_EAVBU Envelope small membrane protein (Protein E) (Glycoprotein 2a) (Protein GP2a)
GP3_EAVBU Glycoprotein 3 (Protein GP3)
GP4_EAVBU Glycoprotein 4 (Protein GP4)
M_EAVBU Membrane protein (Protein M)
GP5_EAVBU Glycoprotein 5 (Protein GP5) (G(L))