title: Inhibition of protein kinase C promotes dengue virus replication.
abstract: BACKGROUND
  Dengue virus (DENV) is a member of the Flaviviridae family, transmitted to human via mosquito. DENV infection is common in tropical areas and occasionally causes life-threatening symptoms. DENV contains a relatively short positive-stranded RNA genome, which encodes ten viral proteins. Thus, the viral life cycle is necessarily rely on or regulated by host factors.
  
  
  METHODS
  In silico analyses in conjunction with in vitro kinase assay were used to study kinases that potentially phosphorylate DENV NS5. Potential kinase was inhibited or activated by a specific inhibitor (or siRNA), or an activator. Results of the inhibition and activation on viral entry/replication and host cell survival were examined.
  
  
  RESULTS
  Our in silico analyses indicated that the non-structural protein 5 (NS5), especially the RNA-dependent RNA polymerase (RdRp) domain, contains conserved phosphorylation sites for protein kinase C (PKC). Phosphorylation of NS5 RdRp was further verified by PKC in vitro kinase assay. Inhibitions of PKC by a PKC-specific chemical inhibitor or siRNA suppressed NS5 phosphorylation in vivo, increased viral replication and reduced viability of the DENV-infected cells. In contrary, activation of PKC effectively suppressed intracellular viral number.
  
  
  CONCLUSIONS
  These results indicated that PKC may act as a restricting mechanism that modulates the DENV replication and represses the viral outburst in the host cells.
authors.affiliation: Department of Biochemistry, Faculty of Sciences, Mahidol University, Bangkok, Thailand. warobon.nop@mtec.or.th.
authors.forename: Warobon
authors.initials: W
authors.lastname: Noppakunmongkolchai
authors.affiliation: Department of Microbiology, Faculty of Sciences, Mahidol University, Bangkok, Thailand. teera.poy@student.mahidol.ac.th.
authors.forename: Teera
authors.initials: T
authors.lastname: Poyomtip
authors.affiliation: Department of Microbiology, Faculty of Sciences, Mahidol University, Bangkok, Thailand. thicha_korn@hotmail.com.
authors.forename: Thichakorn
authors.initials: T
authors.lastname: Jittawuttipoka
authors.affiliation: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Thailand Functional Genetics of Infectious Diseases Unit, Institute, Mahidol University, Bangkok, Thailand. natthanej.lup@mahidol.ac.th.
authors.forename: Natthanej
authors.initials: N
authors.lastname: Luplertlop
authors.affiliation: Institute Pasteur, Functional Genetics of Infectious Diseases Unit, Paris, France. anavaj.sakuntabhai@pasteur.fr.|Centre National de la Recherche Scientifique (CNRS), URA3012, F-75015, Paris, France. anavaj.sakuntabhai@pasteur.fr.|Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand. anavaj.sakuntabhai@pasteur.fr.
authors.forename: Anavaj
authors.initials: A
authors.lastname: Sakuntabhai
authors.affiliation: Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhon Pathom, Thailand. sarin.chi@mahidol.ac.th.|Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand. sarin.chi@mahidol.ac.th.
authors.forename: Sarin
authors.initials: S
authors.lastname: Chimnaronk
authors.affiliation: Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand. siwanon.jir@mahidol.ac.th.|Laboratory for Systems Pharmacology, Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand. siwanon.jir@mahidol.ac.th.
authors.forename: Siwanon
authors.initials: S
authors.lastname: Jirawatnotai
authors.affiliation: Department of Biochemistry, Faculty of Sciences, Mahidol University, Bangkok, Thailand. rutaiwan.toh@mahidol.ac.th.
authors.forename: Rutaiwan
authors.initials: R
authors.lastname: Tohtong
mesh_terms: D000595:Amino Acid Sequence; D002470:Cell Survival / Q000187:drug effects; D016000:Cluster Analysis; D003715:Dengue / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D003716:Dengue Virus / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D020868:Gene Silencing; D054884:Host-Pathogen Interactions; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008954:Models, Biological; D008958:Models, Molecular; D010766:Phosphorylation / Q000187:drug effects; D011487:Protein Conformation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D034741:RNA, Small Interfering / Q000235:genetics; D016415:Sequence Alignment; D017361:Viral Nonstructural Proteins / Q000378:metabolism; D053586:Virus Internalization / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
chemical_list: D007211:Indoles; D008301:Maleimides; C582223:NS5 protein, dengue virus; D034741:RNA, Small Interfering; D017361:Viral Nonstructural Proteins; D011493:Protein Kinase C; C070515:bisindolylmaleimide I