Percavirus

VIRION

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Enveloped, spherical to pleomorphic, 150-200 nm in diameter, T=16 icosahedral symmetry. Capsid consists of 162 capsomers and is surrounded by an amorphous tegument. Glycoproteins complexes are embeded in the lipid envelope.

GENOME

Monopartite, linear, dsDNA genome of about 180 kb. The genome contains terminal and internal reiterated sequences.

GENE EXPRESSION

Each viral transcript usually encodes a single protein and has a promoter/regulatory sequence, a TATA box, a transcription initiation site, a 5' leader sequence of 30-300 bp (not translated), a 3' nontranslated sequence of 10-30 bp, and a poly A signal. There are many gene overlaps. There are only few spliced genes. Some of the expressed ORFs are antisense to each other. Some ORFs can be accessed from more than one promoter. There are some non-coding genes.

REPLICATION

NUCLEAR

Lytic replication:

  1. Attachment of the viral glycoproteins to host receptors mediates endocytosis of the virus into the host cell.
  2. Fusion with the plasma membrane to release the core and the tegument proteins into the host cytoplasm.
  3. The capsid is transported to the nuclear pore where the viral DNA is released into the nucleus.
  4. Transcription of immediate early genes which promote transcription of early genes and protect the virus against innate host immunity.
  5. Transcription of early viral mRNA by host polymerase II, encoding proteins involved in replication of the viral DNA.
  6. A first round of circular genome amplification occurs by bidirectional replication
  7. Synthesis of linear concatemer copies of viral DNA by rolling circle.
  8. Transcription of late mRNAs by host polymerase II, encoding structural proteins.
  9. Assembly of the virus in nuclear viral factories and budding through the inner lamella of the nuclear membrane which has been modified by the insertion of herpes glycoproteins, throughout the Golgi and final release at the plasma membrane.

Latent replication : replication of circular viral episome in tandem with the host cell DNA using the host cell replication machinery.

Host-virus interaction

Adaptive immune response inhibition

The viral interleukin-10 homolog down-regulates the expression of the TAP1 gene (transporter associated with antigen processing), thereby affecting the transport of peptides into the endoplasmic reticulum and subsequent peptide loading by MHC class I molecules.

Apoptosis modulation

The EHV-2 v-FLIP protein (ORF E8) inhibits TNFRSF1A, TNFRSF6, TNFRSF10 and TNFRSF12 induced apoptosis.

Cell-cycle modulation

The UL24 protein induces a cell cycle arrest at G2/M transition through inactivation of the host cyclinB/cdc2 complex .

Splicing inhibition

Modulates the viral and host mRNA expression by exporting unspliced mRNA, thereby inducing alternative splicing.

Matching UniProtKB/Swiss-Prot entries

(all links/actions below point to uniprot.org website)

75 entries grouped by strain (browse by keywords)

74 entries

Equine herpesvirus 2 (strain 86/87) (EHV-2) reference strain

Select_allDeselect_all
CEP2_EHV2 Cytoplasmic envelopment protein 2
CEP3_EHV2 Cytoplasmic envelopment protein 3
CFLA_EHV2 Viral CASP8 and FADD-like apoptosis regulator (v-CFLAR) (Viral FLICE-inhibitory protein) (v-FLIP)
GL_EHV2 Envelope glycoprotein L (gL)
ITP_EHV2 Inner tegument protein
CVC2_EHV2 Capsid vertex component 2
MCP_EHV2 Major capsid protein (MCP)
GN_EHV2 Envelope glycoprotein N
CVC1_EHV2 Capsid vertex component 1
DPOL_EHV2 DNA polymerase catalytic subunit (EC 2.7.7.7)
GB_EHV2 Envelope glycoprotein B (gB)
AN_EHV2 Shutoff alkaline exonuclease (SOX) (EC 3.1.-.-)
HELI_EHV2 DNA replication helicase (EC 3.6.4.-)
HEPA_EHV2 DNA helicase/primase complex-associated protein (HEPA) (Primase-associated factor)
KITH_EHV2 Thymidine kinase (EC 2.7.1.21)
CEP1_EHV2 Cytoplasmic envelopment protein 1
BRLF1_EHV2 Putative transcription activator BRLF1 homolog
DNBI_EHV2 Major DNA-binding protein
DUT_EHV2 Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC 3.6.1.23) (dUTP pyrophosphatase)
IE63_EHV2 Immediate-early phosphoprotein 57
GH_EHV2 Envelope glycoprotein H (gH)
PRIM_EHV2 DNA primase (EC 2.7.7.-)
SCAF_EHV2 Capsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR) [Cleaved into: Assemblin ...
IL10H_EHV2 Viral interleukin-10 homolog (vIL-10)
LTP_EHV2 Large tegument protein deneddylase (EC 3.4.19.12) (EC 3.4.22.-)
GM_EHV2 Envelope glycoprotein M (gM)
TRM1_EHV2 Tripartite terminase subunit 1
TRM2_EHV2 Tripartite terminase subunit 2
TRM3_EHV2 Tripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
TRX1_EHV2 Triplex capsid protein 1
TRX2_EHV2 Triplex capsid protein 2
SCP_EHV2 Small capsomere-interacting protein
RIR2_EHV2 Ribonucleoside-diphosphate reductase small subunit (EC 1.17.4.1) (Ribonucleotide reductase small ...
PORTL_EHV2 Portal protein
TEG7_EHV2 Tegument protein UL51 homolog
VG10_EHV2 Uncharacterized gene 10 protein
VG11_EHV2 Uncharacterized gene 11 protein
VG12_EHV2 Protein E6A
VG13_EHV2 Protein E6C
VG23_EHV2 Uncharacterized gene 23 protein
VG27_EHV2 Uncharacterized gene 27 protein
VGE2_EHV2 Uncharacterized gene E2 protein
VG52_EHV2 Gene 52 protein
VCLAP_EHV2 CARD domain-containing protein E10
VG45_EHV2 Uncharacterized gene 45 protein
UL96_EHV2 Gene 35 protein
VGE1_EHV2 G-protein coupled receptor E1
VG59_EHV2 DNA polymerase processivity factor
UL91_EHV2 Uncharacterized gene 30 protein
VGE4_EHV2 Uncharacterized gene E4 protein
UNG_EHV2 Uracil-DNA glycosylase (UDG) (EC 3.2.2.27) (UNG)
VG75_EHV2 Probable membrane antigen 75 (Tegument protein)
UL49_EHV2 Uncharacterized gene 66 protein
UL79_EHV2 Gene 18 protein
VG51_EHV2 Putative C-type lectin protein 51
UL87_EHV2 Gene 24 protein
VG58_EHV2 Gene 58 protein
VP03_EHV2 Probable membrane antigen 3 (Tegument protein)
UL95_EHV2 Gene 34 protein
VG74_EHV2 G-protein coupled receptor 74
UL24_EHV2 Protein UL24 homolog
VG28_EHV2 Uncharacterized gene 28 protein
VG36_EHV2 Probable inactive protein kinase 38
VG48_EHV2 Tegument protein G48
VG49_EHV2 Uncharacterized gene 49 protein
UL32_EHV2 Packaging protein UL32 homolog
RIR1_EHV2 Ribonucleoside-diphosphate reductase large subunit (R1) (EC 1.17.4.1) (Ribonucleotide reductase ...
TYSY_EHV2 Thymidylate synthase (TS) (TSase) (EC 2.1.1.45)
VGE9_EHV2 Uncharacterized gene E9 protein
VGE3_EHV2 SUSHI domain-containing protein E3
UL92_EHV2 Gene 31 protein
VGE6_EHV2 G-protein coupled receptor E6
NEC1_EHV2 Nuclear egress protein 1
NEC2_EHV2 Nuclear egress protein 2

1 entry

Equine herpesvirus 2 (strain T400/3) (EHV-2)

IL10H_EHV2T Viral interleukin-10 homolog (vIL-10)