The disruption of ND10 during herpes simplex virus infection correlates with the Vmw110- and proteasome-dependent loss of several PML isoforms.
The small nuclear structures known as ND10 or PML nuclear bodies have been implicated in a variety of cellular processes including response to stress and interferons, oncogenesis, and viral infection, but little is known about their biochemical properties. Recently, a ubiquitin-specific protease enzyme (named HAUSP) and a ubiquitin-homology family protein (PIC1) have been found associated with ND10. HAUSP binds strongly to Vmw110, a herpesvirus regulatory protein which has the ability to disrupt ND10, while PIC1 was identified as a protein which interacts with PML, the prototype ND10 protein. We have investigated the role of ubiquitin-related pathways in the mechanism of ND10 disruption by Vmw110 and the effect of virus infection on PML stability. The results show that the disruption of ND10 during virus infection correlates with the loss of several PML isoforms and this process is dependent on active proteasomes. The PML isoforms that are most sensitive to virus infection correspond closely to those which have recently been identified as being covalently conjugated to PIC1. In addition, a large number of PIC1-protein conjugates can be detected following transfection of a PIC1 expression plasmid, and many of these are also eliminated in a Vmw110-dependent manner during virus infection. These observations provide a biochemical mechanism to explain the observed effects of Vmw110 on ND10 and suggest a simple yet powerful mechanism by which Vmw110 might function during virus infection.
Everett
R D
RD
MRC Virology Unit, Glasgow G11 5JR, Scotland. r.everett@vir.gla.ac.uk
Freemont
P
P
Saitoh
H
H
Dasso
M
M
Orr
A
A
Kathoria
M
M
Parkinson
J
J
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003546:Cysteine Endopeptidases / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D007536:Isomerism; D007783:Lactones / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D046988:Proteasome Endopeptidase Complex; D025842:SUMO-1 Protein; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D043222:Ubiquitin Thiolesterase; D044767:Ubiquitin-Protein Ligases; D000076084:Ubiquitin-Specific Peptidase 7; D014452:Ubiquitins / Q000378:metabolism
D015853:Cysteine Proteinase Inhibitors; D017874:Immediate-Early Proteins; D007783:Lactones; D007976:Leupeptins; D009097:Multienzyme Complexes; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D025842:SUMO-1 Protein; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D014452:Ubiquitins; C070576:PML protein, human; C098869:clasto-lactacystin beta-lactone; D044767:Ubiquitin-Protein Ligases; C051804:Vmw110 protein, Human herpesvirus 1; D010450:Endopeptidases; C464569:USP7 protein, human; D043222:Ubiquitin Thiolesterase; D000076084:Ubiquitin-Specific Peptidase 7; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde