Impact of the interaction between herpes simplex virus type 1 regulatory protein ICP0 and ubiquitin-specific protease USP7 on activation of adeno-associated virus type 2 rep gene expression.
Expression of the herpes simplex virus type 1 (HSV-1) regulatory protein ICP0 in transfected cells reactivates rep gene expression from integrated adeno-associated virus (AAV) type 2 genomes via a mechanism that requires both its RING finger and USP7 interaction domains. In this study, we found that the rep reactivation defect of USP7-binding-negative ICP0 mutants can be overcome by further deletion of sequences in the C-terminal domain of ICP0, indicating that binding of USP7 to ICP0 is not directly required. Unlike the case in transfected cells, only the RING finger domain of ICP0 was essential for rep gene reactivation during HSV-1 infection. However, mutants unable to bind to USP7 activate HSV-1 gene expression and reactivate rep gene expression with reduced efficiencies. These results further elucidate the role of ICP0 as a helper factor for AAV replication and illustrate that care is required when extrapolating from the properties of ICP0 in transfection assays to events occurring during HSV-1 infection.
INSERM U649, CHU Hotel-Dieu, Nantes, France.
Marie-Claude
MC
Geoffroy
Gilliane
G
Chadeuf
Anne
A
Orr
Anna
A
Salvetti
Roger D
RD
Everett
D015153:Blotting, Western; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism*; D000229:Dependovirus / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D017353:Gene Deletion; D015870:Gene Expression; D006367:HeLa Cells; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D017434:Protein Structure, Tertiary; D012235:Rhodamines; D014162:Transfection; D043222:Ubiquitin Thiolesterase; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000076084:Ubiquitin-Specific Peptidase 7; D014764:Viral Proteins / Q000378:metabolism*
D004268:DNA-Binding Proteins; D005456:Fluorescent Dyes; D017874:Immediate-Early Proteins; D012235:Rhodamines; D014764:Viral Proteins; C068734:rep proteins, Adeno-associated virus 2; D044767:Ubiquitin-Protein Ligases; C051804:Vmw110 protein, Human herpesvirus 1; D010450:Endopeptidases; C464569:USP7 protein, human; D043222:Ubiquitin Thiolesterase; D000076084:Ubiquitin-Specific Peptidase 7; D016650:Fluorescein-5-isothiocyanate