title: Regulated nuclear targeting of cauliflower mosaic virus.
abstract: The mature cauliflower mosaic virus (CaMV) capsid protein (CP), if expressed in the absence of other viral proteins, is transported into the plant cell nucleus by the action of a nuclear localization signal (NLS) close to the N terminus. In contrast, virus particles do not enter the nucleus, but dock at the nuclear membrane, a process inhibited by anti-NLS antibodies or by GTP gamma S, and apparently mediated by interaction of CP with host importin alpha. The very acidic N-terminal extension of the viral CP precursor inhibits nuclear targeting of the protein and hence the precursor is localized in the cytoplasm. We hypothesize that this provides a control mechanism which ensures that the CP precursor is used for virus assembly in the cytoplasm and that only mature virus particles reach the nuclear pore.
authors.affiliation: Friedrich Miescher Institute, PO Box 2543,CH-4002 Basel, Switzerland1.
authors.forename: Aletta
authors.initials: A
authors.lastname: Karsies
authors.affiliation: Institut für Biologie II, Zellbiologie, Universität Freiburg, 79104 Freiburg, Germany2.
authors.forename: Thomas
authors.initials: T
authors.lastname: Merkle
authors.affiliation: Institute of Genetics, Martin-Luther University, 06120 Halle, Germany3.
authors.forename: Boris
authors.initials: B
authors.lastname: Szurek
authors.affiliation: Institute of Genetics, Martin-Luther University, 06120 Halle, Germany3.
authors.forename: Ulla
authors.initials: U
authors.lastname: Bonas
authors.affiliation: Friedrich Miescher Institute, PO Box 2543,CH-4002 Basel, Switzerland1.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hohn
authors.affiliation: Centre de Recherche en Infectiologie, Université Laval, Ste-Foy, Qc, G1V 4G2, Canada4.
authors.forename: Denis
authors.initials: D
authors.lastname: Leclerc
mesh_terms: D000595:Amino Acid Sequence; D000906:Antibodies / Q000494:pharmacology; D015153:Blotting, Western; D002213:Capsid / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D017796:Caulimovirus / Q000302:isolation & purification / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D028884:Karyopherins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009685:Nuclear Envelope / Q000821:virology; D019913:Nuclear Localization Signals; D011485:Protein Binding; D020079:Terminal Repeat Sequences; D014026:Nicotiana / Q000235:genetics; D014162:Transfection; D019065:Virus Assembly
chemical_list: D000906:Antibodies; D028884:Karyopherins; D019913:Nuclear Localization Signals; D016244:Guanosine 5'-O-(3-Thiotriphosphate)