title: Coordination of KSHV latent and lytic gene control by CTCF-cohesin mediated chromosome conformation.
abstract: Herpesvirus persistence requires a dynamic balance between latent and lytic cycle gene expression, but how this balance is maintained remains enigmatic. We have previously shown that the Kaposi's Sarcoma-Associated Herpesvirus (KSHV) major latency transcripts encoding LANA, vCyclin, vFLIP, v-miRNAs, and Kaposin are regulated, in part, by a chromatin organizing element that binds CTCF and cohesins. Using viral genome-wide chromatin conformation capture (3C) methods, we now show that KSHV latency control region is physically linked to the promoter regulatory region for ORF50, which encodes the KSHV immediate early protein RTA. Other linkages were also observed, including an interaction between the 5' and 3' end of the latency transcription cluster. Mutation of the CTCF-cohesin binding site reduced or eliminated the chromatin conformation linkages, and deregulated viral transcription and genome copy number control. siRNA depletion of CTCF or cohesin subunits also disrupted chromosomal linkages and deregulated viral latent and lytic gene transcription. Furthermore, the linkage between the latent and lytic control region was subject to cell cycle fluctuation and disrupted during lytic cycle reactivation, suggesting that these interactions are dynamic and regulatory. Our findings indicate that KSHV genomes are organized into chromatin loops mediated by CTCF and cohesin interactions, and that these inter-chromosomal linkages coordinate latent and lytic gene control.
authors.affiliation: The Wistar Institute, Philadelphia, Pennsylvania, United States of America.
authors.forename: Hyojeung
authors.initials: H
authors.lastname: Kang
authors.forename: Andreas
authors.initials: A
authors.lastname: Wiedmer
authors.forename: Yan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Erle
authors.initials: E
authors.lastname: Robertson
authors.forename: Paul M
authors.initials: PM
authors.lastname: Lieberman
mesh_terms: D000076246:CCCTC-Binding Factor; D018797:Cell Cycle Proteins / Q000502:physiology*; D045744:Cell Line, Tumor; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D005809:Genes, Regulator / Q000235:genetics; D005814:Genes, Viral / Q000502:physiology*; D019288:Herpesvirus 8, Human / Q000235:genetics* / Q000276:immunology; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics*; D016393:Lymphoma, B-Cell / Q000235:genetics; D009690:Nucleic Acid Conformation / Q000187:drug effects; D012097:Repressor Proteins / Q000502:physiology*; D015534:Trans-Activators / Q000235:genetics*; D017735:Virus Latency / Q000502:physiology*; D016335:Zinc Fingers / Q000502:physiology; D000097722:Cohesins
chemical_list: D000076246:CCCTC-Binding Factor; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D017874:Immediate-Early Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D000097722:Cohesins; C000619697:CTCF protein, human; C116742:ORF 50 transactivator; C417604:Rta protein, Human herpesvirus 8