Lytic Reactivation of the Kaposi's Sarcoma-Associated Herpesvirus (KSHV) Is Accompanied by Major Nucleolar Alterations.

The nucleolus is a subnuclear compartment whose primary function is the biogenesis of ribosomal subunits. Certain viral infections affect the morphology and composition of the nucleolar compartment and influence ribosomal RNA (rRNA) transcription and maturation. However, no description of nucleolar morphology and function during infection with Kaposi's sarcoma-associated herpesvirus (KSHV) is available to date.

Latently KSHV-Infected Cells Promote Further Establishment of Latency upon Superinfection with KSHV.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-related virus which engages in two forms of infection: latent and lytic. Latent infection allows the virus to establish long-term persistent infection, whereas the lytic cycle is needed for the maintenance of the viral reservoir and for virus spread. By using recombinant KSHV viruses encoding mNeonGreen and mCherry fluorescent proteins, we show that various cell types that are latently-infected with KSHV can be superinfected, and that the new incoming viruses establish latent infection.

The Portal Vertex of KSHV Promotes Docking of Capsids at the Nuclear Pores.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-related herpesvirus. Like other herpesviruses, the KSHV icosahedral capsid includes a portal vertex, composed of 12 protein subunits encoded by open reading frame (ORF) 43, which enables packaging and release of the viral genome into the nucleus through the nuclear pore complex (NPC). Capsid vertex-specific component (CVSC) tegument proteins, which directly mediate docking at the NPCs, are organized on the capsid vertices and are enriched on the portal vertex.

Targeting the Kaposi's sarcoma-associated herpesvirus genome with the CRISPR-Cas9 platform in latently infected cells.

Background: Kaposi's sarcoma-associated herpesvirus (KSHV) is a transforming gammaherpesvirus. Like other herpesviruses, KSHV infection is for life long and there is no treatment that can cure patients from the virus. In addition, there is an urgent need to target viral genes to study their role during the infection cycle.

The KSHV portal protein ORF43 is essential for the production of infectious viral particles.

Herpesvirus capsid assembly involves cleavage and packaging of the viral genome. The Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 43 (orf43) encodes a putative portal protein. The portal complex functions as a gate through which DNA is packaged into the preformed procapsids, and is injected into the cell nucleus upon infection.

Nucleolar stress enhances lytic reactivation of the Kaposi's sarcoma-associated herpesvirus.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a human tumorigenic virus exhibiting two forms of infection, latent and lytic. Latent infection is abortive and allows the virus to establish lifelong infection, while lytic infection is productive, and is needed for virus dissemination within the host and between hosts. Latent infection may reactivate and switch towards the lytic cycle.

Graphene-Based "Hot Plate" for the Capture and Destruction of the Herpes Simplex Virus Type 1.

The study of graphene-based antivirals is still at a nascent stage and the photothermal antiviral properties of graphene have yet to be studied. Here, we design and synthesize sulfonated magnetic nanoparticles functionalized with reduced graphene oxide (SMRGO) to capture and photothermally destroy herpes simplex virus type 1 (HSV-1). Graphene sheets were uniformly anchored with spherical magnetic nanoparticles (MNPs) of varying size between ∼5 and 25 nm.

The Kaposi's-sarcoma-associated herpesvirus orf35 gene product is required for efficient lytic virus reactivation.

Kaposi's sarcoma-associated herpesvirus (KSHV) is implicated in the etiology of several human malignancies. KSHV open reading frame (orf) 35 encodes a conserved gammaherpesvirus protein with an, as yet, unknown function. Employing the bacterial artificial chromosome (BAC) system, we generated a recombinant viral clone that fails to express ORF35 (BAC16-ORF35-stop) but preserves intact adjacent and overlapping reading frames.

Viral Bcl-2 Encoded by the Kaposi's Sarcoma-Associated Herpesvirus Is Vital for Virus Reactivation.

Unlabelled: The Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 16 (orf16) encodes a viral Bcl-2 (vBcl-2) protein which shares sequence and functional homology with the Bcl-2 family. Like its cellular homologs, vBcl-2 protects various cell types from apoptosis and can also negatively regulate autophagy. vBcl-2 is transcribed during lytic infection; however, its exact function has not been determined to date.

Fluorescent tagging and cellular distribution of the Kaposi's sarcoma-associated herpesvirus ORF45 tegument protein.

Unlabelled: Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is a cancer-related human virus, classified as a member of the Gammaherpesvirinae subfamily. We report here the construction of a dual fluorescent-tagged KSHV genome (BAC16-mCherry-ORF45), which constitutively expresses green fluorescent protein (GFP) and contains the tegument multifunctional ORF45 protein as a fusion protein with monomeric Cherry fluorescent protein (mCherry). We confirmed that this virus is properly expressed and correctly replicates and that the mCherry-ORF45 protein is incorporated into the virions.

The nucleolar PICT-1/GLTSCR2 protein forms homo-oligomers.

The human "protein interacting with carboxyl terminus 1" (PICT-1), also designated as the "glioma tumor suppressor candidate region 2 gene product", GLTSCR2, is a nucleolar protein whose activity is, as yet, unknown. Contradictory results regarding the role of PICT-1 in cancer have been reported, and PICT-1 has been suggested to function either as a tumor suppressor protein or as an oncogene. In this study, we demonstrate self-association of PICT-1.

Herpes simplex virus type-1 attachment inhibition by functionalized graphene oxide.

Graphene oxide and its derivatives have lately been the subject of increased attention in the field of bioscience and biotechnology. In this article, we report on the use of graphene oxide (GO) derivatives to inhibit herpes simplex virus type-1 (HSV-1) infections, mimicking the cell surface receptor heparan sulfate, and the GO derivatives compete with the latter in binding HSV-1. The inhibition does not affect cell-to-cell spreading.

Nucleolar localization of GLTSCR2/PICT-1 is mediated by multiple unique nucleolar localization sequences.

The human glioma tumor suppressor candidate region 2 gene product, GLTSCR2, also called 'protein interacting with carboxyl terminus 1' (PICT-1), has been implicated in the regulation of two major tumor suppressor proteins, PTEN and p53, and reported to bind the membrane-cytoskeleton regulator of cell signaling, Merlin. PICT-1 is a nucleolar protein, conserved among eukaryotes, and its yeast homolog has been functionally associated with ribosomal RNA processing. By means of confocal microscopy of EGFP and myc-tagged PICT-1 fusion proteins, we delineate that the nucleolar localization of PICT-1 is mediated by two independent nucleolar localization sequences (NoLS).

Human herpesvirus 8 is not detectable in lesions of large plaque parapsoriasis, and in early-stage sporadic, familial, and juvenile cases of mycosis fungoides.

Background: Human herpesvirus (HHV) 8, an essential etiologic agent of Kaposi sarcoma, is also associated with several lymphoproliferative disorders. The involvement of HHV 8 in mycosis fungoides (MF) and large plaque parapsoriasis (LPP) is controversial, with contradictory reports from various countries worldwide.

Objective: We sought to investigate the presence of the HHV 8 genome in skin lesions of LPP and early-stage sporadic, familial, and juvenile MF in patients in Israel.

GLTSCR2/PICT-1, a putative tumor suppressor gene product, induces the nucleolar targeting of the Kaposi's sarcoma-associated herpesvirus KS-Bcl-2 protein.

KS-Bcl-2, encoded by Kaposi's sarcoma-associated herpesvirus (KSHV), is a structural and functional homologue of the Bcl-2 family of apoptosis regulators. Like several other Bcl-2 family members, KS-Bcl-2 protects cells from apoptosis and autophagy. Using a yeast two-hybrid screen and coimmunoprecipitation assays, we identified a novel KS-Bcl-2-interacting protein, referred to as protein interacting with carboxyl terminus 1 (PICT-1), encoded by a candidate tumor suppressor gene, GLTSCR2.

Linking the Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8) to human malignancies.

In 1994, the Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8) was identified as the etiologic agent of Kaposi's sarcoma (KS). KSHV has since been associated with two additional malignancies: primary effusion lymphoma and multicentric Castleman's disease. In this chapter, we describe the current understanding of the pathogenesis, transmission, and prevalence of KSHV, and its association mainly with KS.