Open AccessOpen reading frame 73 is required for herpesvirus saimiri A11-S4 episomal persistence
Author(s) -
Michael A. Calderwood,
Rob White,
Rhoswyn A. Griffiths,
Adrian Whitehouse
Publication year - 2005
Publication title -
journal of general virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.55
H-Index - 167
eISSN - 1465-2099
pISSN - 0022-1317
DOI - 10.1099/vir.0.81230-0
Subject(s) - biology , virology , plasmid , orfs , open reading frame , genome , genetics , recombinant dna , virus latency , population , gene , virus , viral replication , peptide sequence , demography , sociology
Herpesvirus saimiri (HVS) establishes a latent infection in which the viral genome persists as a non-integrated episome. Analysis has shown that only open reading frames (ORFs) 71–73 are transcribed in an in vitro model of HVS latency. ORF73 also colocalizes with HVS genomic DNA on host mitotic chromosomes and maintains the stability of HVS terminal-repeat-containing plasmids. However, it is not known whether ORF73 is the only HVS-encoded protein required for episomal maintenance. In this study, the elements required for episomal maintenance in the context of a full-length HVS genome were examined by mutational analysis. A recombinant virus, HVS-BACΔ71-73, lacking the latency-associated genes was unable to persist in a dividing cell population. However, retrofitting an ORF73 expression cassette into the recombinant virus rescued episomal maintenance. This indicates that ORF73 is the key trans -acting factor for episomal persistence and efficient establishment of a latent infection.