title: Topology and cellular localization of the small hydrophobic protein of avian metapneumovirus.
abstract: The small hydrophobic protein (SH) is a type II integral membrane protein that is packaged into virions and is only present in certain paramyxoviruses including metapneumovirus. In addition to a highly divergent primary sequence, SH proteins vary significantly in size amongst the different viruses. Human respiratory syncytial virus (HRSV) encodes the smallest SH protein consisting of only 64 amino acids, while metapneumoviruses have the longest SH protein ranging from 174 to 179 amino acids in length. Little is currently known about the cellular localization and topology of the metapneumovirus SH protein. Here we characterize for the first time metapneumovirus SH protein with respect to topology, subcellular localization, and transport using avian metapneumovirus subgroup C (AMPV-C) as a model system. We show that AMPV-C SH is an integral membrane protein with N(in)C(out) orientation located in both the plasma membrane as well as within intracellular compartments, which is similar to what has been described previously for SH proteins of other paramyxoviruses. Furthermore, we demonstrate that AMPV-C SH protein localizes in the endoplasmic reticulum (ER), Golgi, and cell surface, and is transported through ER-Golgi secretory pathway.
authors.affiliation: Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, United States.
authors.forename: Qiji
authors.initials: Q
authors.lastname: Deng
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Weng
authors.forename: Wuxun
authors.initials: W
authors.lastname: Lu
authors.forename: Andrew
authors.initials: A
authors.lastname: Demers
authors.forename: Minxun
authors.initials: M
authors.lastname: Song
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Yu
authors.forename: Feng
authors.initials: F
authors.lastname: Li
mesh_terms: D002462:Cell Membrane / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000737:chemistry; D006056:Golgi Apparatus / Q000737:chemistry; D029121:Metapneumovirus / Q000737:chemistry* / Q000378:metabolism*; D021381:Protein Transport; D015682:Retroviridae Proteins, Oncogenic / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D015682:Retroviridae Proteins, Oncogenic; C056150:small hydrophobic protein, virus