title: A novel mosquito ubiquitin targets viral envelope protein for degradation and reduces virion production during dengue virus infection.
abstract: Dengue virus (DENV) is a mosquito-borne flavivirus that causes significant human disease and mortality in the tropics and subtropics. By examining the effects of virus infection on gene expression, and interactions between virus and vector, new targets for prevention of infection and novel treatments may be identified in mosquitoes. We previously performed a microarray analysis of the Aedes aegypti transcriptome during infection with DENV and found that mosquito ubiquitin protein Ub3881 (AAEL003881) was specifically and highly down-regulated. Ubiquitin proteins have multiple functions in insects, including marking proteins for proteasomal degradation, regulating apoptosis and mediating innate immune signaling.
  
  
  
  We used qRT-PCR to quantify gene expression and infection, and RNAi to reduce Ub3881 expression. Mosquitoes were infected with DENV through blood feeding. We transfected DENV protein expression constructs to examine the effect of Ub3881 on protein degradation. We used site-directed mutagenesis and transfection to determine what amino acids are involved in Ub3881-mediated protein degradation. Immunofluorescence, Co-immunoprecipitation and Western blotting were used to examine protein interactions and co-localization.
  
  
  
  The overexpression of Ub3881, but not related ubiquitin proteins, decreased DENV infection in mosquito cells and live Ae. aegypti. The Ub3881 protein was demonstrated to be involved in DENV envelope protein degradation and reduce the number of infectious virions released.
  
  
  
  We conclude that Ub3881 has several antiviral functions in the mosquito, including specific viral protein degradation.
  
  
  
  Our data highlights Ub3881 as a target for future DENV prevention strategies in the mosquito transmission vector.
authors.affiliation: Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, United States.
authors.forename: Andrea
authors.initials: A
authors.lastname: Troupin
authors.affiliation: Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, United States.
authors.forename: Berlin
authors.initials: B
authors.lastname: Londono-Renteria
authors.affiliation: Foundational Sciences, Central Michigan University College of Medicine, Mount Pleasant, MI 48859, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Conway
authors.affiliation: Department of Tropical Medicine, Tulane University School of Public Health, New Orleans, LA 70112, United States.
authors.forename: Erin
authors.initials: E
authors.lastname: Cloherty
authors.affiliation: Department of Tropical Medicine, Tulane University School of Public Health, New Orleans, LA 70112, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Jameson
authors.affiliation: Biosecurity Research Institute, Kansas State University, Manhattan, KS 66506, United States; Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Higgs
authors.affiliation: Biosecurity Research Institute, Kansas State University, Manhattan, KS 66506, United States; Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506, United States.
authors.forename: Dana L
authors.initials: DL
authors.lastname: Vanlandingham
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States; Howard Hughes Medical Institute, Chevy Chase, MD 20815, United States.
authors.forename: Erol
authors.initials: E
authors.lastname: Fikrig
authors.affiliation: Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, United States. Electronic address: tonya.colpitts@uscmed.sc.edu.
authors.forename: Tonya M
authors.initials: TM
authors.lastname: Colpitts
mesh_terms: D000330:Aedes / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002460:Cell Line; D003715:Dengue / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control / Q000821:virology*; D003716:Dengue Virus / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D007113:Immunity, Innate / Q000235:genetics; D047468:Immunoprecipitation / Q000379:methods; D007303:Insect Vectors / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics; D059467:Transcriptome / Q000235:genetics; D025801:Ubiquitin / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000235:genetics / Q000378:metabolism*
chemical_list: D025801:Ubiquitin; D014759:Viral Envelope Proteins; D046988:Proteasome Endopeptidase Complex
keywords: Arbovirus; Dengue virus; Mosquito transmission; Protein degradation; Ubiquitin