title: Membrane orientation and oligomerization of the small hydrophobic protein of human respiratory syncytial virus.
abstract: Previous work has demonstrated that the small hydrophobic (SH) protein of human respiratory syncytial virus (RSV) A2 strain is a 64 amino acid integral membrane protein that accumulates intracellularly as an unglycosylated major species (SH0), a minor species truncated at the amino terminus and two N-glycosylated species one of which contains a further addition of polylactosamine. In this study, the membrane orientation of SH0 was mapped by trypsinization of intact RSV-infected cells followed by washout, lysis and immunoprecipitation of protected fragments with antisera specific for the protein termini. This showed that the C terminus is extracellular and the SH protein was not detectably palmitylated. Analysis of the SH protein by sedimentation on sucrose gradients showed that it rapidly assembles into a homo-oligomer that co-sediments with the F protein tetramer. Interestingly, all forms of the SH protein were found in the oligomeric fraction. Chemical cross-linking generated species which appeared to represent dimers, trimers, tetramers and pentamers as well as a minor species of 180K which might correspond to the oligomeric form detected by sucrose gradient sedimentation.
authors.affiliation: Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: P L
authors.initials: PL
authors.lastname: Collins
authors.forename: G
authors.initials: G
authors.lastname: Mottet
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D015707:HN Protein; D006801:Humans; D046911:Macromolecular Substances; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification; D010449:Peptide Mapping; D011499:Protein Processing, Post-Translational; D012136:Respiratory Syncytial Viruses / Q000378:metabolism*; D014357:Trypsin; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015707:HN Protein; D046911:Macromolecular Substances; D010446:Peptide Fragments; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C116204:attachment protein G; D008715:Methionine; D014357:Trypsin