TABLE 1.

PRV gene functions

GeneSize (kDa)Common nameProposed function(s)aStructural roleCore
ORF1.2 35.3UnknownVirionNo
ORF1 21.8UnknownVirionNo
UL54 40.4ICP27Transcription modulation; cell-cell spread; RNA-binding proteinNonstructuralYes
UL53 33.8gKViral egress (secondary envelopment); glycoprotein K; type III membrane protein; gK/UL20 together inhibit glycoprotein-mediated membrane fusionVirion (envelope)No
UL52 103.3 DNA replication; primase subunit of UL5/UL8/UL52 complex NonstructuralYes
UL51 25Viral egress (secondary envelopment); tegument protein, potentially palmytoilatedVirion (tegument)Yes
UL50 28.6dUTPasedUTPaseNonstructuralYes
UL49.5 10.1gNImmune evasion (TAP inhibitor); glycoprotein N; type I membrane protein; complexed with gMVirion (envelope)Yes
UL49 25.9VP22Interacts with C-terminal domains of gE & gM; tegument proteinVirion (tegument)No
UL48 45.1VP16, α-TIFGene regulation (transactivator); viral egress (secondary envelopment); tegument proteinVirion (tegument)No
UL47 80.4VP13/14Viral egress (secondary envelopment); tegument proteinVirion (tegument)No
UL46 75.5VP11/12Unknown; tegument proteinVirion (tegument)No
UL27 100.2gBViral entry (fusion); cell-cell spread; glycoprotein B; type I membrane proteinVirion (envelope)Yes
UL28 78.9ICP18.5DNA cleavage and packaging; component of the UL15/UL28 terminaseCapsid precursorYes
UL29 125.3ICP8DNA replication and recombination; binds single stranded DNANonstructuralYes
UL30 115.3DNA replication; DNA polymerase subunit of UL30/UL42 holoenzymeNonstructuralYes
UL31 30.4Viral egress (nuclear egress); present only in primary enveloped virion; interacts with UL34Primary virion (tegument)Yes
UL32 51.6 DNA packaging; efficient localization of capsids to replication compartments Capsid precursorYes
UL33 12.7 DNA cleavage and packaging; associates with UL28 and UL15 NonstructuralYes
UL34 28.1Viral egress (nuclear egress); present only in primary enveloped virion; tail-anchored type II nuclear membrane protein; interacts with UL31Primary virion (envelope)Yes
UL35 11.5VP26Surface capsid proteinVirion (capsid)Yes
UL36 324.4VP1/2Viral egress (capsid tegumentation); large tegument protein; interacts with UL37 and capsidVirion (tegument)Yes
UL37 98.2Viral egress (capsid tegumentation); interacts with UL36Virion (tegument)Yes
UL38 40VP19c Minor capsid protein; UL38/UL18/UL18 triplex component Virion (capsid)Yes
UL39 91.1RR1Nucleotide synthesis; large subunit of ribonucleotide reductaseNonstructuralYes
UL40 34.4RR2Nucleotide synthesis; small subunit of ribonucleotide reductaseNonstructuralNo
UL41 40.1VHSGene regulation, RNAse, degrades host and viral mRNAsVirion (tegument)No
UL42 40.3DNA replication; polymerase accessory subunit of UL30/UL42 holoenzymeNonstructuralYes
UL43 38.1Inhibits glycoprotein-mediated membrane fusion; type III membrane proteinVirion (envelope)No
UL44 51.2gCViral entry (virion attachment); glycoprotein C; type I membrane protein; binds to heparan sulfateVirion (envelope)No
UL26.5 28.2pre-VP22a Major scaffold protein; substrate for UL26 protease; capsid formation and maturationCapsid precursorYes
UL26 54.6VP24 Minor scaffold protein; capsid maturation proteaseCapsid precursorYes
UL25 57.4Capsid-associated protein; required for capsid assemblyVirion (capsid)Yes
UL24 19.1Unknown; type III membrane protein?Yes
UL23 35TKNucleotide synthesis; thymidine kinase; selectively activates acyclovirNonstructuralNo
UL22 71.9gHViral entry (fusion); cell-cell spread; glycoprotein H; type I membrane protein; complexed with gLVirion (envelope)Yes
UL21 55.2Unknown, capsid-associated tegument protein; interacts with UL16Virion (tegument)Yes
UL20 16.7Viral egress; type III membrane protein; required for gK processing; gK/UL20 together inhibit glycoprotein-mediated membrane fusion?No
UL19 146VP5Major capsid protein; forms hexons and pentonsVirion (capsid)Yes
UL18 31.6VP23 Minor capsid protein; UL38/UL18/UL18 triplex component Virion (capsid)Yes
UL17 64.2DNA cleavage and encapsidationVirion (inner capsid)Yes
UL16 34.8Unknown; tegument protein; interacts with UL21Virion (tegument)Yes
UL15 79.1 DNA cleavage/encapsidation; terminase subunit of the UL15/UL28 terminase; interacts with UL33, UL28 & UL6 Capsid precursorYes
UL14 17.9Unknown?Yes
UL13 41.1VP18.8Unknown; protein-serine/threonine kinaseVirion (tegument)Yes
UL12 51.3ANDNA recombination; alkaline exonuclease?Yes
UL11 7Viral egress (secondary envelopment); membrane-associated tegument proteinVirion (tegument)Yes
UL10 41.5gMInhibits glycoprotein-mediated membrane fusion; glycoprotein M; type III membrane protein; C terminus interacts with tegument protein UL49; complexed with gNVirion (envelope)Yes
UL9 90.5OBP Sequence-specific ori-binding protein, ATP-dependent helicase motifNonstructuralNo
UL8.5 51OPBCC-terminal domain of UL9?No
UL8 71.2 DNA replication; part of UL5/UL8/UL52 helicase/primase complex NonstructuralYes
UL7 29Unknown?Yes
UL6 70.3 Capsid protein; portal protein; docking site for terminase Virion (capsid)Yes
UL5 92.1 DNA replication; part of UL5/UL8/UL52 helicase/primase complex; helicase motifNon-structuralYes
UL4 15.8Unknown?No
UL3.5 24Viral egress (secondary envelopment); membrane-associated protein?No
UL3 25.6UnknownNonstructuralNo
UL2 33UNG DNA repair; Uracil-DNA glycosylaseNonstructuralYes
UL1 16.5gLViral entry (fusion); cell-cell spread; glycoprotein L; membrane anchored via complex with gHVirion (envelope)Yes
EP0 43.8ICP0Gene regulation (transactivator); early protein; ND10 structure modulation; contains RING finger motifVirionNo
IE180 148.6ICP4Gene regulation (transactivator); immediate-early proteinNonstructuralNo
US1 39.6RSp40/ICP22Unknown; HSV-1 homolog (ICP22) acts as regulator of gene expression?No
US3 (minor) 42.9PKMinor form of protein kinase (53-kDa mobility); inhibits apoptosis; mitochondrial targeting motif?No
US3 (major) 36.9PKViral egress (nuclear egress); inhibits apoptosis; major form of protein kinase (41-kDa mobility); found in both primary and secondary enveloped virionsVirion (tegument)No
US4 53.7gGUnknown; glycoprotein G (secreted)SecretedNo
US6 44.3gDViral entry (cellular receptor binding protein); glycoprotein D; type I membrane proteinVirion (envelope)No
US7 38.7gICell-cell spread; glycoprotein I; type I membrane protein; complexed with gEVirion (envelope)No
US8 62.4gECell-cell spread; glycoprotein E; type I membrane protein; complexed with gI; C-terminus interacts with UL49; protein sorting in axonsVirion (envelope)No
US9 11.311KProtein sorting in axons; type II tail-anchored membrane proteinVirion (envelope)No
US2 27.728KTegument protein; membrane associated proteinVirion (tegument)No
  • a Gene functions in italics rely primarily on studies of the HSV-1 homolog.