title: Palmitoylation is required for intracellular trafficking of influenza B virus NB protein and efficient influenza B virus growth in vitro.
abstract: All influenza viruses bud and egress from lipid rafts within the apical plasma membrane of infected epithelial cells. As a result, all components of progeny virions must be transported to these lipid rafts for assembly and budding. Although the mechanism of transport for other influenza proteins has been elucidated, influenza B virus (IBV) glycoprotein NB subcellular localization and transport are not understood completely. To address the aforementioned properties of NB, a series of trafficking experiments were conducted. Here, we showed that NB co-localized with markers specific for the endoplasmic reticulum (ER) and Golgi region. The data from chemical treatment of NB-expressing cells by Brefeldin A, a fungal antibiotic and a known chemical inhibitor of the protein secretory pathway, further confirmed that NB is transported through the ER-Golgi pathway as it restricted NB localization to the perinuclear region. Using NB deletion mutants, the hydrophobic transmembrane domain was identified as being required for NB transport to the plasma membrane. Furthermore, palmitoylation was also required for transport of NB to the plasma membrane. Systematic mutation of cysteines to serines in NB demonstrated that cysteine 49, likely in a palmitoylated form, is also required for transport to the plasma membrane. Surprisingly, further analysis demonstrated that in vitro replication of NBC49S mutant virus was delayed relative to the parental IBV. The results demonstrated that NB is the third influenza virus protein to have been shown to be palmitoylated and together these findings may aid in future studies aimed at elucidating the function of NB.
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA.|Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Demers
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Ran
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Qiji
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Brody
authors.initials: B
authors.lastname: Edman
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Wuxun
authors.initials: W
authors.lastname: Lu
authors.affiliation: Center for Infectious Disease Research and Vaccinology, South Dakota State University, Brookings, SD 57007, USA.|Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA.|Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D003545:Cysteine / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005814:Genes, Viral; D006056:Golgi Apparatus / Q000378:metabolism; D009981:Influenza B virus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D054878:Lipoylation; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014779:Virus Replication
chemical_list: C051094:NB glycoprotein, Influenza B virus; D014764:Viral Proteins; D003545:Cysteine