The viral packaging motor potentiates Kaposi's sarcoma-associated herpesvirus gene expression late in infection

• Published in: PLoS pathogens Vol. 19; no. 4; p. e1011163
• Main Authors: McCollum, Chloe O, Didychuk, Allison L, Liu, Dawei, Murray-Nerger, Laura A, Cristea, Ileana M, Glaunsinger, Britt A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.04.2023; Public Library of Science (PLoS)
• Subjects: Analysis; Artificial chromosomes; Biology and life sciences; Care and treatment; Catalytic activity; Complications and side effects; CRISPR; Cytomegalovirus; Deoxyribonucleic acid; DNA; DNA-directed RNA polymerase; Engineering and Technology; Flow cytometry; Gene deletion; Gene Expression; Gene Expression Regulation, Viral; Genes; Genetic aspects; Genetic research; Genetic screening; Genetic transcription; Genomes; Health aspects; Herpes; Herpes viruses; Herpesvirus 8, Human - genetics; Herpesvirus 8, Human - metabolism; Herpesvirus diseases; Infection; Infections; Kaposi's sarcoma; Kaposis sarcoma; Labeling; Localization; Mass spectrometry; Mass spectroscopy; Medicine and Health Sciences; Ontology; Packaging; Prevention; Proteins; Research and Analysis Methods; Risk factors; RNA; RNA polymerase; RNA polymerase II; Sarcoma; Scientific imaging; siRNA; Transcription; Viral Genome Packaging; Viral Proteins - genetics; Viral Proteins - metabolism; Virus Replication; Viruses; United States
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1011163

β- and γ-herpesviruses transcribe their late genes in a manner distinct from host transcription. This process is directed by a complex of viral transcriptional activator proteins that hijack cellular RNA polymerase II and an unknown set of additional factors. We employed proximity labeling coupled with mass spectrometry, followed by CRISPR and siRNA screening to identify proteins functionally associated with the Kaposi's sarcoma-associated herpesvirus (KSHV) late gene transcriptional complex. These data revealed that the catalytic subunit of the viral DNA packaging motor, ORF29, is both dynamically associated with the viral transcriptional activator complex and potentiates gene expression late in infection. Through genetic mutation and deletion of ORF29, we establish that its catalytic activity potentiates viral transcription and is required for robust accumulation of essential late proteins during infection. Thus, we propose an expanded role for ORF29 that encompasses its established function in viral packaging and its newly discovered contributions to viral transcription and late gene expression in KSHV.