Betaherpesvirinae (taxid:10357)
VIRION

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 140-240 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.
ENZYMES
- DNA-dependent DNA polymerase
- DNA primase
- Tegument deneddylase (Peptidase C76)
- Assemblin (Peptidase S21)
- Kinase
- Helicase
- Ribonucleoside-diphosphate reductase
- Thymidine kinase
- Uracil-DNA glycosylase
REPLICATION
NUCLEAR
Lytic replication:
- Attachment of the viral glycoproteins to host receptors mediates endocytosis of the virus into the host cell.
- Fusion with the plasma membrane to release the core and the tegument proteins into the host cytoplasm.
- The capsid is transported to the nuclear pore where the viral DNA is released into the nucleus.
- Transcription of immediate early genes which promote transcription of early genes and protect the virus against innate host immunity.
- Transcription of early viral mRNA by host polymerase II, encoding proteins involved in replication of the viral DNA.
- A first round of circular genome amplification occurs by bidirectional replication
- Synthesis of linear concatemer copies of viral DNA by rolling circle.
- Transcription of late mRNAs by host polymerase II, encoding structural proteins.
- 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
Beta-herpesviruses have evolved different strategies to inhibit the host adaptive immune response. For example, HCMV US2 destroys two components of the MHC class II pathway, HLA-DR-alpha and DM-alpha, preventing recognition by CD4+ T cells. Mouse cytomegalovirus (MCMV) uses m152 and m06 encoded proteins to inhibit surface expression of MHC I molecules .
Apoptosis modulation
Apoptosis is very often modulated (and usually inhibited) by beta-herpesviruses. Human cytomegalovirus (HCMV) viral inhibitor of caspase-8-induced apoptosis (from gene UL36) plays a role in the inhibition of apoptosis by interacting with the pro-domain of pro-caspase-8/CASP8 and thus preventing its activation . Murine cytomegalovirus m38.5 protein interacts with host Bax in infected cells and thus inhibits Bax-mediated cell death .
Autophagy modulation
Several beta-herpesviruses are able to inhibit host autophagy process, such as HCMV protein TRS1 via its interaction with host Beclin 1 .
Cell-cycle modulation
The UL24 protein that is present in all herpesvirus subfamilies (alpha, beta and gamma-herpesviruses) induces a cell cycle arrest at G2/M transition through inactivation of the host cyclinB/cdc2 complex .
Innate immune response inhibition
Herpes viruses inhibit the cascade leading to production of interferon-beta by mainly targeting the host IRF3 protein. For example, HCMV targets host IRF3 protein with the viral pp65 protein .
Host splicing inhibition
Modulates the 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)756 entries grouped by strain
144 entries
Human cytomegalovirus (strain AD169) (HHV-5) (Human herpesvirus 5) reference strain
166 entries
Human cytomegalovirus (strain Merlin) (HHV-5) (Human herpesvirus 5) reference strain
96 entries
Human herpesvirus 6A (strain Uganda-1102) (HHV-6 variant A) (Human B lymphotropic virus) reference strain
97 entries
Human herpesvirus 6B (strain Z29) (HHV-6 variant B) (Human B lymphotropic virus) reference strain
63 entries
Human herpesvirus 7 (strain JI) (HHV-7) (Human T lymphotropic virus) reference strain
15 entries
Murid herpesvirus 1 (strain Smith) (MuHV-1) (Mouse cytomegalovirus) reference strain
5 entries
Guinea pig cytomegalovirus (strain 22122) (GPCMV) reference strain
3 entries
Murid herpesvirus 1 (strain K181) (MuHV-1) (Mouse cytomegalovirus) reference strain
2 entries
Rat cytomegalovirus (strain Maastricht) reference strain
1 entry
Rat cytomegalovirus (isolate England) (RCMV-E) (Murid herpesvirus 8) reference strain
49 entries
Human cytomegalovirus (strain AD169) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain Merlin) (HHV-5) (Human herpesvirus 5)
1 entry
Human herpesvirus 6A (strain Uganda-1102) (HHV-6 variant A) (Human B lymphotropic virus)
34 entries
Elephantid herpesvirus 1 (isolate Asian elephant/Berlin/Kiba/1998) (EIHV-1) (Elephant endotheliotropic herpesvirus)
28 entries
Human cytomegalovirus (strain Towne) (HHV-5) (Human herpesvirus 5)
1 entry
Murid herpesvirus 1 (strain Smith) (MuHV-1) (Mouse cytomegalovirus)
13 entries
Human herpesvirus 6B (HHV-6 variant B) (Human B lymphotropic virus)
11 entries
Human herpesvirus 6A (strain GS) (HHV-6 variant A) (Human B lymphotropic virus)
2 entries
Murid herpesvirus 1 (strain K181) (MuHV-1) (Mouse cytomegalovirus)
4 entries
Tupaiid herpesvirus (strain 2) (TuHV-2) (Herpesvirus tupaia (strain 2))
2 entries
Human cytomegalovirus (strain Toledo) (HHV-5) (Human herpesvirus 5)
2 entries
Rhesus cytomegalovirus (strain 68-1) (RhCMV)
2 entries
Simian cytomegalovirus (strain Colburn)
1 entry
Human cytomegalovirus (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 1042) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 119) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 2387) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 4654) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 5035) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 5040) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 5160) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain 5508) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain Eisenhardt) (HHV-5) (Human herpesvirus 5)
1 entry
Human cytomegalovirus (strain PT) (HHV-5) (Human herpesvirus 5)
1 entry
Human herpesvirus 7 (strain MUK) (HHV-7) (Human T lymphotropic virus)
1 entry
Human herpesvirus 7 (strain RK) (HHV-7) (Human T lymphotropic virus)
1 entry
Tupaiid herpesvirus 1 (strain 1) (TuHV-1) (Herpesvirus tupaia (strain 1))
Aotine betaherpesvirus 1 taxid:50290
Caviid betaherpesvirus 2 taxid:33706
Cynomolgus cytomegalovirus taxid:1919083
Elephant endotheliotropic herpesvirus 4 taxid:548914
Elephant endotheliotropic herpesvirus 5 taxid:768738
Elephantid herpesvirus 1 taxid:146015
Elephantid herpesvirus 1 (isolate Asian elephant/Berlin/Kiba/1998) taxid:654902
Protein | ModelArchive |
Protein ORF A | ma-jd-viral-36498 |
Protein ORF B | ma-jd-viral-13328 |
Protein U4 | ma-jd-viral-13325 |
Protein U68 | ma-jd-viral-52996 |
Tegument protein UL51 homolog | ma-jd-viral-35765 |
Guinea pig cytomegalovirus (strain 22122) taxid:103920
Protein | ModelArchive |
Envelope glycoprotein B (gB) | ma-jd-viral-31188 |
Envelope glycoprotein H (gH) | ma-jd-viral-16930 |
Envelope glycoprotein L (gL) | ma-jd-viral-00343 |
Protein GP96 | ma-jd-viral-18507 |
Human betaherpesvirus 6A taxid:32603
Human betaherpesvirus 7 taxid:10372
Human cytomegalovirus taxid:10359
Human cytomegalovirus (strain 5508) taxid:69168
Protein | ModelArchive |
Envelope glycoprotein L (gL) | ma-jd-viral-00341 |
Human cytomegalovirus (strain AD169) taxid:10360
Human cytomegalovirus (strain Merlin) taxid:295027
Human cytomegalovirus (strain Toledo) taxid:311339
Human cytomegalovirus (strain Towne) taxid:10363
Human herpesvirus 6A (strain GS) taxid:10369
Protein | ModelArchive |
Envelope glycoprotein H (gH) | ma-jd-viral-16932 |
Human herpesvirus 6A (strain Uganda-1102) taxid:10370
Human herpesvirus 6B taxid:32604
Human herpesvirus 6B (strain Z29) taxid:36351
Human herpesvirus 7 (strain JI) taxid:57278
Human herpesvirus 7 (strain MUK) taxid:57279
Protein | ModelArchive |
Triplex capsid protein 2 | ma-jd-viral-04783 |
Human herpesvirus 7 (strain RK) taxid:262398
Protein | ModelArchive |
U21 glycoprotein (gp60) | ma-jd-viral-36538 |