Publications by authors named "Richard J Courtney"

Herpes simplex virus type 1 (HSV-1) UL37 is a 1123 amino acid tegument protein that self-associates and binds to the tegument protein UL36 (VP1/2). Studies were undertaken to identify regions of UL37 involved in these protein-protein interactions. Coimmunoprecipitation assays showed that residues within the carboxy-terminal half of UL37, amino acids 568-1123, are important for interaction with UL36.

View Article and Find Full Text PDF

HSV-1 virions contain a proteinaceous layer termed the tegument that lies between the nucleocapsid and viral envelope. The molecular mechanisms that facilitate incorporation of tegument proteins are poorly characterized. The tegument protein VP22 interacts with VP16 and the cytoplasmic tail of glycoprotein E (gE).

View Article and Find Full Text PDF

The molecular mechanisms responsible for the addition of tegument proteins into nascent herpesvirus particles are poorly understood. To better understand the tegumentation process of herpes simplex virus type 1 (HSV-1) virions, we initiated studies that showed the tegument protein pUL46 (VP11/12) has a similar cellular localization to the membrane-associated tegument protein VP22. Using membrane flotation analysis we found that pUL46 associates with membranes in both the presence and absence of other HSV-1 proteins.

View Article and Find Full Text PDF

The product of the UL11 gene of HSV-1 is a small, membrane-bound tegument protein with features that are conserved among all herpesviruses. For all viruses examined, mutants lacking this protein (or its homolog) have budding defects and accumulate capsids in the cytoplasm of the infected cell. UL11 binds to the cytoplasmic faces of host membranes via N-terminal myristate and nearby palmitate moieties.

View Article and Find Full Text PDF

Herpes simplex virus type 1 (HSV-1) virions contain a proteinaceous layer termed the tegument that lies between the nucleocapsid and viral envelope. The mechanisms underlying tegumentation remain largely undefined for all herpesviruses. Using glutathione S-transferase (GST) pulldowns and coimmunoprecipitation studies, we have identified a domain of the tegument protein VP22 that facilitates interaction with VP16.

View Article and Find Full Text PDF

The assembly of the tegument of herpes simplex virus type 1 (HSV-1) is a complex process that involves a number of events at various sites within virus-infected cells. Our studies focused on determining whether tegument proteins, VP1/2 and UL37, are added to capsids located within the nucleus. Capsids were isolated from the nuclear fraction of HSV-1-infected cells and purified by rate-zonal centrifugation to separate B capsids (containing the scaffold proteins and no viral DNA) and C capsids (containing DNA and no scaffold proteins).

View Article and Find Full Text PDF

Herpes simplex virus type 1 (HSV-1) virions, contain a proteinaceous layer termed the tegument that lies between the nucleocapsid and viral envelope. Current evidence suggests that viral glycoprotein tails play a role in the recruitment of tegument-coated capsids to the site of final envelopment; vesicles derived from the trans-Golgi network. We have identified an interaction between VP22, an abundant tegument protein and the cytoplasmic tail of glycoprotein E (gE).

View Article and Find Full Text PDF

The UL11 gene of herpes simplex virus type 1 encodes a 96-amino-acid tegument protein that is myristylated, palmitylated, and phosphorylated and is found on the cytoplasmic faces of nuclear, Golgi apparatus-derived, and plasma membranes of infected cells. Although this protein is thought to play a role in virus budding, its specific function is unknown. Purified virions were found to contain approximately 700 copies of the UL11 protein per particle, making it an abundant component of the tegument.

View Article and Find Full Text PDF

We have investigated the interactions and consequences of superinfecting and coreplication of human papillomavirus (HPV) and herpes simplex virus (HSV) in human epithelial organotypic (raft) culture tissues. In HPV-positive tissues, HSV infection and replication induced significant cytopathic effects (CPE), but the tissues were able to recover and maintain a certain degree of tissue integrity and architecture. HPV31b not only maintained the episomal state of its genomic DNA but also maintained its genomic copy number even during times of extensive HSV-induced CPE.

View Article and Find Full Text PDF

The product of the U(L)11 gene of herpes simplex virus type 1 (HSV-1) is a 96-amino-acid tegument protein that accumulates on the cytoplasmic face of internal membranes. Although it is thought to be important for nucleocapsid envelopment and egress, the actual function of this protein is unknown. Previous studies focused on the characterization of sequence elements within the UL11 protein that function in membrane binding and trafficking to the Golgi apparatus.

View Article and Find Full Text PDF

Tegument proteins of herpes simplex virus type 1 (HSV-1) are hypothesized to contain the functional information required for the budding or envelopment process proposed to occur at cytoplasmic compartments of the host cell. One of the most abundant tegument proteins of HSV-1 is the U(L)49 gene product, VP22, a 38-kDa protein of unknown function. To study its subcellular localization, a VP22-green fluorescent protein chimera was expressed in transfected human melanoma (A7) cells.

View Article and Find Full Text PDF