title: The highly conserved human cytomegalovirus UL136 ORF generates multiple Golgi-localizing protein isoforms through differential translation initiation.
abstract: The UL133-UL138 locus in the unique long b' (ULb') region of the human cytomegalovirus (HCMV) genome is considered to play certain roles in viral replication, dissemination and latency in a host cell type-dependent manner. Here we characterized the proteins encoded by UL136, one of the open reading frames (ORFs) in the locus. Comparative sequence analysis of UL136 among clinical isolates and laboratory strains indicates that its predicted amino-acid sequence is highly conserved. A polyclonal antibody against UL136 proteins (pUL136s) was raised against its carboxy-terminal region and this antibody specifically recognized at least five UL136-encoded protein isoforms of 29-17 kDa both in HCMV-infected cells and in cells transfected with a construct expressing pUL136. Immunofluorescence analysis with this antibody revealed localization of pUL136 in the Golgi apparatus. Analysis of several pUL136 mutants indicated that the putative transmembrane domain of pUL136 is required for its Golgi localization. Mutational analysis of multiple AUG codons in UL136 demonstrated that translation initiation from these AUG codons contributes in the generation of pUL136 isoforms.
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan.
authors.forename: Huanan
authors.initials: H
authors.lastname: Liao
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan; Department of Pediatrics, College of Medicine, The Catholic University of Korea, Republic of Korea.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan.
authors.forename: Rikita
authors.initials: R
authors.lastname: Kondo
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan.
authors.forename: Marei
authors.initials: M
authors.lastname: Katata
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Imadome
authors.affiliation: Department of Reproductive Biology, National Research Institute for Child Health and Development, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Miyado
authors.affiliation: Department of Virology I, National Institute of Infectious Diseases, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: Department of Infectious Diseases, National Research Institute for Child Health and Development, Japan. Electronic address: nakamura-hry@ncchd.go.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D003587:Cytomegalovirus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003586:Cytomegalovirus Infections / Q000821:virology*; D006056:Golgi Apparatus / Q000821:virology*; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D020033:Protein Isoforms; D014764:Viral Proteins
keywords: Human cytomegalovirus; Translation initiation; UL136