Enveloped, spherical to pleomorphic, 120-200 nm in diameter T=16 icosahedral symmetry. The capsid consists of 162 capsomers and is surrounded by an amorphous tegument. Glycoproteins complexes are embedded in the lipid envelope.


Monopartite, linear, dsDNA genome of about 175 kbp. The genome contains terminal and internal reiterated sequences.


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.

There are three types of genes: immediate-early, early and late. The immediate-early genes are transcribed immediately after infection and ensure the transcription of early genes, which encode the proteins necessary for the viral replication. The late genes mostly encode structural proteins. Standing apart are genes expressed during latency.



Lytic replication:

  1. Attachment of the viral gB, gC, gD and gH proteins 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

Cell-cycle modulation

The conserved UL24 family of human alpha, beta and gamma herpesviruses induces a cell cycle arrest at G2/M transition through inactivation of the host cyclinB/cdc2 complex. Marek disease virus encodes an UL24 homolog that should fullfill this role.

Apoptosis modulation

MEQ antagonizes apoptosis possibly through regulation of its downstream target genes involved in apoptotic and/or anti-apoptotic pathways.

Host splicing inhibition

GaHV-2 MDV068 is an alternative splicing regulator of host mRNA.

Matching UniProtKB/Swiss-Prot entries

115 entries grouped by strain (browse by keywords)

90 entries

Gallid herpesvirus 2 (strain Chicken/Md5/ATCC VR-987) (GaHV-2) (Marek's disease herpesvirus type 1) reference strain

RIR1_GAHVM Ribonucleoside-diphosphate reductase large subunit (R1) (EC (Ribonucleotide reductase ...
PP24_GAHVM Phosphoprotein pp24
SCAF_GAHVM Capsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR) (Virion structural ...
TEG3_GAHVM Tegument protein UL14 homolog
TRM2_GAHVM Tripartite terminase subunit 2
TEG1_GAHVM Tegument protein UL46 homolog (Tegument protein VP11/12 homolog)
TEG7_GAHVM Tegument protein UL51 homolog
UL24_GAHVM Protein UL24 homolog
VG85_GAHVM Uncharacterized gene 85 protein
SHUT_GAHVM Virion host shutoff protein (Vhs) (EC 3.1.27.-)
US10_GAHVM Virion protein US10 homolog
NEC2_GAHVM Nuclear egress protein 2
ITP_GAHVM Inner tegument protein
OBP_GAHVM Replication origin-binding protein (OBP) (OriBP)
MEQ_GAHVM Oncoprotein MEQ (MEQ)
PAP_GAHVM DNA polymerase processivity factor (DNA-binding protein UL42) (Polymerase accessory protein) (PAP)
NP03_GAHVM Nuclear phosphoprotein UL3 homolog
IL8H_GAHVM Viral interleukin-8 homolog (vIL8)
VG01_GAHVM Uncharacterized gene 1 protein
VG02_GAHVM Uncharacterized gene 2 protein
TEG6_GAHVM Tegument protein UL55 homolog
VG72_GAHVM Uncharacterized gene 72 protein
VG71_GAHVM Uncharacterized gene 71 protein
US02_GAHVM Protein US2 homolog
US03_GAHVM Protein kinase US3 homolog (EC
VLIP_GAHVM Virulence factor MDV010 (Viral lipase homolog) (vLIP)
VG06A_GAHVM Uncharacterized gene 6a protein
TRX2_GAHVM Triplex capsid protein 2
VG04_GAHVM Uncharacterized gene 4 protein
KITH_GAHVM Thymidine kinase (EC
UL13_GAHVM Serine/threonine-protein kinase UL13 homolog (EC
PP38_GAHVM Phosphoprotein pp38
UNG_GAHVM Uracil-DNA glycosylase (UDG) (EC (UNG)
VG86_GAHVM Uncharacterized gene 86 protein
TRX1_GAHVM Triplex capsid protein 1
SCP_GAHVM Small capsomere-interacting protein
RIR2_GAHVM Ribonucleoside-diphosphate reductase small subunit (EC (Ribonucleotide reductase small ...
GB_GAHVM Envelope glycoprotein B (gB)
DPOL_GAHVM DNA polymerase catalytic subunit (EC (EC
CEP1_GAHVM Cytoplasmic envelopment protein 1
DNBI_GAHVM Major DNA-binding protein
CEP2_GAHVM Cytoplasmic envelopment protein 2
HEPA_GAHVM DNA helicase/primase complex-associated protein (HEPA) (Primase-associated factor)
EV45_GAHVM Envelope protein UL45 homolog
GD_GAHVM Envelope glycoprotein D (gD)
GC_GAHVM Envelope glycoprotein C homolog (A antigen) (Glycoprotein A) (GA) (Secretory glycoprotein GP57-65)
ICP4_GAHVM Major viral transcription factor ICP4 homolog (Immediate-early protein IE175)
CVC1_GAHVM Capsid vertex component 1
AN_GAHVM Alkaline nuclease (EC 3.1.-.-)
GH_GAHVM Envelope glycoprotein H (gH)
GL_GAHVM Envelope glycoprotein L (gL)
GI_GAHVM Envelope glycoprotein I
ICP22_GAHVM Transcriptional regulator ICP22 homolog (Immediate early ICP22-like protein)
GE_GAHVM Envelope glycoprotein E (gE)
HELI_GAHVM DNA replication helicase (EC 3.6.4.-)
MCP_GAHVM Major capsid protein (MCP)
GK_GAHVM Envelope glycoprotein K
LTP_GAHVM Large tegument protein deneddylase (EC (EC 3.4.22.-)
ICP27_GAHVM mRNA export factor ICP27 homolog (Transcriptional regulator IE63 homolog)
NEC1_GAHVM Nuclear egress protein 1
GM_GAHVM Envelope glycoprotein M (gM)
PORTL_GAHVM Portal protein
MB43_GAHVM Membrane protein UL43 homolog
UL32_GAHVM Packaging protein UL32 homolog
VG69_GAHVM Uncharacterized gene 69 protein
VG82_GAHVM Uncharacterized gene 82 protein
VG81_GAHVM Uncharacterized gene 81 protein
DUT_GAHVM Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP pyrophosphatase)
VG90_GAHVM Uncharacterized gene 90 protein
VG97_GAHVM Uncharacterized gene 97 protein
VP22_GAHVM Tegument protein VP22
TG21_GAHVM Tegument protein UL21 homolog
TEG5_GAHVM Tegument protein UL47 homolog
VP16_GAHVM Tegument protein VP16 homolog (Alpha trans-inducing protein) (Alpha-TIF) (ORF10 protein) (Tegument ...
VG12_GAHVM Uncharacterized gene 12 protein
VG07_GAHVM Uncharacterized gene 7 protein
UL4_GAHVM Nuclear protein UL4 homolog
UL20_GAHVM Protein UL20 homolog
VG11_GAHVM Uncharacterized gene 11 protein
VG06B_GAHVM Uncharacterized gene 6b protein
VG83_GAHVM Uncharacterized gene 83 protein
PRIM_GAHVM DNA primase (EC 2.7.7.-)
TRM3_GAHVM Tripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
TRM1_GAHVM Tripartite terminase subunit 1
VG87_GAHVM Uncharacterized gene 87 protein
VG09_GAHVM Uncharacterized gene 9 protein
VG93_GAHVM Uncharacterized gene 93 protein
CEP3_GAHVM Cytoplasmic envelopment protein 3
CVC2_GAHVM Capsid vertex component 2
GN_GAHVM Envelope glycoprotein N

12 entries

Gallid herpesvirus 2 (strain GA) (GaHV-2) (Marek's disease herpesvirus type 1)

US453_GAHVG Uncharacterized 16.6 kDa protein
US384_GAHVG Uncharacterized 14.2 kDa protein
US426_GAHVG Uncharacterized 15.7 kDa protein
US03_GAHVG Serine/threonine-protein kinase US3 homolog (EC
U1053_GAHVG Uncharacterized 40.6 kDa protein
US420_GAHVG Uncharacterized 15.5 kDa protein
ICP4_GAHVG Major viral transcription factor ICP4 homolog (Immediate-early protein IE175)
GC_GAHVG Envelope glycoprotein C homolog (A antigen) (Glycoprotein A) (GA) (Secretory glycoprotein GP57-65)
GL_GAHVG Envelope glycoprotein L (gL)
US10_GAHVG Virion protein US10 homolog
US441_GAHVG Uncharacterized 16.7 kDa protein
VP38_GAHVG 38 kDa phosphoprotein (Phosphoprotein pp38)

4 entries

Gallid herpesvirus 2 (strain RB-1b) (GaHV-2) (Marek's disease herpesvirus type 1)

GC_GAHVR Envelope glycoprotein C homolog (A antigen) (Glycoprotein A) (GA) (Secretory glycoprotein GP57-65)
GH_GAHVR Envelope glycoprotein H (gH)
KITH_GAHVR Thymidine kinase (EC
GB_GAHVR Envelope glycoprotein B (gB)

2 entries

Gallid herpesvirus 2 (strain bc-1) (GaHV-2) (Marek's disease herpesvirus type 1)

EV45_GAHVB Envelope protein UL45 homolog
GC_GAHVB Envelope glycoprotein C homolog (A antigen) (Glycoprotein A) (GA) (Secretory glycoprotein GP57-65)

2 entries

Meleagrid herpesvirus 1 (MeHV-1) (Turkey herpesvirus)

KITH_MEHV1 Thymidine kinase (EC
GH_MEHV1 Envelope glycoprotein H (gH)

2 entries

Meleagrid herpesvirus 1 (strain FC126) (MeHV-1) (Turkey herpesvirus)

KITH_MEHVF Thymidine kinase (EC
GC_MEHVF Envelope glycoprotein C homolog (A antigen) (Glycoprotein A)

2 entries

Meleagrid herpesvirus 1 (strain H2) (MeHV-1) (Turkey herpesvirus)

GC_MEHVH Envelope glycoprotein C homolog (A antigen) (Glycoprotein A)
EV45_MEHVH Envelope protein UL45 homolog (23.5 kDa protein)

1 entry

Gallid herpesvirus 2 (strain MD11/75C/R2) (GaHV-2) (Marek's disease herpesvirus type 1)

VP38_GAHVN 38 kDa phosphoprotein (Phosphoprotein pp38)