title: 4EBP-Dependent Signaling Supports West Nile Virus Growth and Protein Expression.
abstract: West Nile virus (WNV) is a (+) sense, single-stranded RNA virus in theFlavivirusgenus. WNV RNA possesses anm7GpppNm5' cap with 2'-O-methylation that mimics host mRNAs preventing innate immune detection and allowing the virus to translate its RNA genome through the utilization of cap-dependent translation initiation effectors in a wide variety of host species. Our prior work established the requirement of the host mammalian target of rapamycin complex 1 (mTORC1) for optimal WNV growth and protein expression; yet, the roles of the downstream effectors of mTORC1 in WNV translation are unknown. In this study, we utilize gene deletion mutants in the ribosomal protein kinase called S6 kinase (S6K) and eukaryotic translation initiation factor 4E-binding protein (4EBP) pathways downstream of mTORC1 to define the role of mTOR-dependent translation initiation signals in WNV gene expression and growth. We now show that WNV growth and protein expression are dependent on mTORC1 mediated-regulation of the eukaryotic translation initiation factor 4E-binding protein/eukaryotic translation initiation factor 4E-binding protein (4EBP/eIF4E) interaction and eukaryotic initiation factor 4F (eIF4F) complex formation to support viral growth and viral protein expression. We also show that the canonical signals of mTORC1 activation including ribosomal protein s6 (rpS6) and S6K phosphorylation are not required for WNV growth in these same conditions. Our data suggest that the mTORC1/4EBP/eIF4E signaling axis is activated to support the translation of the WNV genome.
authors.affiliation: Department of Immunology and Microbiology, University of Colorado Graduate School, Aurora, CO 80045, USA. katherineshives@gmail.com.
authors.forename: Katherine D
authors.initials: KD
authors.lastname: Shives
authors.affiliation: Department of Medicine, Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA. aaron.massey@ucdenver.edu.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Massey
authors.affiliation: Department of Immunology and Microbiology, University of Colorado Graduate School, Aurora, CO 80045, USA. nicholas.may@ucdenver.edu.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: May
authors.affiliation: Department of Immunology and Microbiology, University of Colorado Graduate School, Aurora, CO 80045, USA. thomas.morrison@ucdenver.edu.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Morrison
authors.affiliation: Department of Immunology and Microbiology, University of Colorado Graduate School, Aurora, CO 80045, USA. david.beckham@ucdenver.edu.|Department of Medicine, Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA. david.beckham@ucdenver.edu.
authors.forename: J David
authors.initials: JD
authors.lastname: Beckham
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002460:Cell Line; D039642:Eukaryotic Initiation Factors; D017353:Gene Deletion; D054884:Host-Pathogen Interactions; D051379:Mice; D018345:Mice, Knockout; D010750:Phosphoproteins / Q000172:deficiency / Q000378:metabolism*; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000172:deficiency / Q000378:metabolism; D015398:Signal Transduction; D014764:Viral Proteins / Q000096:biosynthesis*; D014779:Virus Replication; D014902:West Nile virus / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C499527:Eif4ebp1 protein, mouse; D039642:Eukaryotic Initiation Factors; D010750:Phosphoproteins; D014764:Viral Proteins; D038762:Ribosomal Protein S6 Kinases, 70-kDa; C448959:ribosomal protein S6 kinase, 70kD, polypeptide 2
keywords: RNA; West Nile virus; protein synthesis; translation