title: G-quadruplex-interacting compounds alter latent DNA replication and episomal persistence of KSHV.
abstract: Kaposi's sarcoma associated herpesvirus (KSHV) establishes life-long latent infection by persisting as an extra-chromosomal episome in the infected cells and by maintaining its genome in dividing cells. KSHV achieves this by tethering its epigenome to the host chromosome by latency associated nuclear antigen (LANA), which binds in the terminal repeat (TR) region of the viral genome. Sequence analysis of the TR, a GC-rich DNA element, identified several potential Quadruplex G-Rich Sequences (QGRS). Since quadruplexes have the tendency to obstruct DNA replication, we used G-quadruplex stabilizing compounds to examine their effect on latent DNA replication and the persistence of viral episomes. Our results showed that these G-quadruplex stabilizing compounds led to the activation of dormant origins of DNA replication, with preferential bi-directional pausing of replications forks moving out of the TR region, implicating the role of the G-rich TR in the perturbation of episomal DNA replication. Over time, treatment with PhenDC3 showed a loss of viral episomes in the infected cells. Overall, these data show that G-quadruplex stabilizing compounds retard the progression of replication forks leading to a reduction in DNA replication and episomal maintenance. These results suggest a potential role for G-quadruplex stabilizers in the treatment of KSHV-associated diseases.
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ch416, Bronx, NY 10461, USA.
authors.forename: Advaitha
authors.initials: A
authors.lastname: Madireddy
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
authors.forename: Pravinkumar
authors.initials: P
authors.lastname: Purushothaman
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Loosbroock
authors.affiliation: Department of Microbiology and the Tumor Virology Program of the Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104, USA.
authors.forename: Erle S
authors.initials: ES
authors.lastname: Robertson
authors.affiliation: Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Ch416, Bronx, NY 10461, USA carl.schildkraut@einstein.yu.edu.
authors.forename: Carl L
authors.initials: CL
authors.lastname: Schildkraut
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, 1664 N Virginia Street, MS 320, Reno, NV 89557, USA scverma@medicine.nevada.edu.
authors.forename: Subhash C
authors.initials: SC
authors.lastname: Verma
mesh_terms: D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects*; D054856:G-Quadruplexes / Q000187:drug effects*; D016679:Genome, Viral / Q000187:drug effects; D057809:HEK293 Cells; D019288:Herpesvirus 8, Human / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D006801:Humans; D010957:Plasmids / Q000187:drug effects*; D011166:Porphyrins / Q000494:pharmacology; D018741:Replication Origin; D020079:Terminal Repeat Sequences; D017735:Virus Latency
chemical_list: D011166:Porphyrins; C021096:tetra(4-N-methylpyridyl)porphine
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