title: NEDDylation is essential for Kaposi's sarcoma-associated herpesvirus latency and lytic reactivation and represents a novel anti-KSHV target.
abstract: Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), which are aggressive malignancies associated with immunocompromised patients. For many non-viral malignancies, therapeutically targeting the ubiquitin proteasome system (UPS) has been successful. Likewise, laboratory studies have demonstrated that inhibition of the UPS might provide a promising avenue for the treatment of KSHV-associated diseases. The largest class of E3 ubiquitin ligases are the cullin-RING ligases (CRLs) that are activated by an additional ubiquitin-like protein, NEDD8. We show that pharmacological inhibition of NEDDylation (using the small molecule inhibitor MLN4924) is cytotoxic to PEL cells by inhibiting NF-κB. We also show that CRL4B is a novel regulator of latency as its inhibition reactivated lytic gene expression. Furthermore, we uncovered a requirement for NEDDylation during the reactivation of the KSHV lytic cycle. Intriguingly, inhibition prevented viral DNA replication but not lytic cycle-associated gene expression, highlighting a novel mechanism that uncouples these two features of KSHV biology. Mechanistically, we show that MLN4924 treatment precluded the recruitment of the viral pre-replication complex to the origin of lytic DNA replication (OriLyt). These new findings have revealed novel mechanisms that regulate KSHV latency and reactivation. Moreover, they demonstrate that inhibition of NEDDylation represents a novel approach for the treatment of KSHV-associated malignancies.
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors: David J
authors: DJ
authors: Hughes
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors: Jennifer J
authors: JJ
authors: Wood
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors: Brian R
authors: BR
authors: Jackson
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors: Belinda
authors: B
authors: Baquero-Pérez
authors: School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom.
authors: Adrian
authors: A
authors: Whitehouse
mesh_terms: D045744:Cell Line, Tumor; D003517:Cyclopentanes / Q000494:pharmacology*; D004261:DNA Replication / Q000187:drug effects; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D057809:HEK293 Cells; D019288:Herpesvirus 8, Human / Q000502:physiology*; D006801:Humans; D000075687:NEDD8 Protein; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*; D012514:Sarcoma, Kaposi / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*; D014775:Virus Activation / Q000187:drug effects* / Q000235:genetics
chemical_list: D003517:Cyclopentanes; D004279:DNA, Viral; D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; D016328:NF-kappa B; D011743:Pyrimidines; D014452:Ubiquitins; C539933:pevonedistat