title: Human Cytomegalovirus Infection Upregulates the Mitochondrial Transcription and Translation Machineries.
abstract: Infection with human cytomegalovirus (HCMV) profoundly affects cellular metabolism. Like in tumor cells, HCMV infection increases glycolysis, and glucose carbon is shifted from the mitochondrial tricarboxylic acid cycle to the biosynthesis of fatty acids. However, unlike in many tumor cells, where aerobic glycolysis is accompanied by suppression of mitochondrial oxidative phosphorylation, HCMV induces mitochondrial biogenesis and respiration. Here, we affinity purified mitochondria and used quantitative mass spectrometry to determine how the mitochondrial proteome changes upon HCMV infection. We found that the mitochondrial transcription and translation systems are induced early during the viral replication cycle. Specifically, proteins involved in biogenesis of the mitochondrial ribosome were highly upregulated by HCMV infection. Inhibition of mitochondrial translation with chloramphenicol or knockdown of HCMV-induced ribosome biogenesis factor MRM3 abolished the HCMV-mediated increase in mitochondrially encoded proteins and significantly impaired viral growth under bioenergetically restricting conditions. Our findings demonstrate how HCMV manipulates mitochondrial biogenesis to support its replication.
  
  
  OBJECTIVE
  Human cytomegalovirus (HCMV), a betaherpesvirus, is a leading cause of morbidity and mortality during congenital infection and among immunosuppressed individuals. HCMV infection significantly changes cellular metabolism. Akin to tumor cells, in HCMV-infected cells, glycolysis is increased and glucose carbon is shifted from the tricarboxylic acid cycle to fatty acid biosynthesis. However, unlike in tumor cells, HCMV induces mitochondrial biogenesis even under aerobic glycolysis. Here, we have affinity purified mitochondria and used quantitative mass spectrometry to determine how the mitochondrial proteome changes upon HCMV infection. We find that the mitochondrial transcription and translation systems are induced early during the viral replication cycle. Specifically, proteins involved in biogenesis of the mitochondrial ribosome were highly upregulated by HCMV infection. Inhibition of mitochondrial translation with chloramphenicol or knockdown of HCMV-induced ribosome biogenesis factor MRM3 abolished the HCMV-mediated increase in mitochondrially encoded proteins and significantly impaired viral growth. Our findings demonstrate how HCMV manipulates mitochondrial biogenesis to support its replication.
authors.affiliation: Department of Medicine, University of Cambridge Clinical School, Addenbrookes Hospital, Cambridge, United Kingdom sharon.karniely@weizmann.ac.il.
authors.forename: S
authors.initials: S
authors.lastname: Karniely
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
authors.forename: M P
authors.initials: MP
authors.lastname: Weekes
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Antrobus
authors.affiliation: MRC, Mitochondrial Biology Unit, Cambridge, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Rorbach
authors.affiliation: MRC, Mitochondrial Biology Unit, Cambridge, United Kingdom.
authors.forename: L
authors.initials: L
authors.lastname: van Haute
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Y
authors.initials: Y
authors.lastname: Umrania
authors.affiliation: Paterson Institute for Cancer Research, University of Manchester, Withington, Manchester, United Kingdom.
authors.forename: D L
authors.initials: DL
authors.lastname: Smith
authors.affiliation: Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom.
authors.forename: R J
authors.identifier: http://orcid.org/0000-0002-6799-1182
authors.initials: RJ
authors.lastname: Stanton
authors.affiliation: MRC, Mitochondrial Biology Unit, Cambridge, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Minczuk
authors.affiliation: Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
authors.forename: P J
authors.initials: PJ
authors.lastname: Lehner
authors.affiliation: Department of Medicine, University of Cambridge Clinical School, Addenbrookes Hospital, Cambridge, United Kingdom.
authors.forename: J H
authors.initials: JH
authors.lastname: Sinclair
mesh_terms: D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000473:pathology; D054884:Host-Pathogen Interactions; D006801:Humans; D013058:Mass Spectrometry; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000032:analysis*; D014176:Protein Biosynthesis; D020543:Proteome / Q000032:analysis; D014158:Transcription, Genetic
chemical_list: D024101:Mitochondrial Proteins; D020543:Proteome