title: Highly localized tracks of human immunodeficiency virus type 1 Nef in the nucleus of cells of a human CD4+ T-cell line.
abstract: A human T-cell line constitutively expressing the nef gene from the human immunodeficiency virus type 1 SF2 isolate was used to examine the distribution of the Nef protein in the nucleus. High-resolution immunogold labeling/electron microscopic studies with polyclonal anti-Nef antibodies on nef+ and nef- cells revealed that a small fraction of Nef is in the nucleus and it is localized in specific curvilinear tracks that extend between the nuclear envelope and the nucleoplasm. An examination of the sequence of the SF2 nef gene revealed a putative nuclear targeting sequence that was previously found in several other eukaryotic nucleoplasmic proteins. The nuclear localization of Nef suggests a potential nuclear function for this protein. The presence of Nef in distinct nuclear tracks suggests that Nef is transported along a specific pathway that extends from the nuclear envelope into the nucleoplasm. A previous study [Meier, U. T. & Blobel, G. (1992) Cell 70, 127-138] has shown that the nucleolar protein of rat liver cells (Nopp140) shuttles from the nucleolus to the nuclear envelope on distinct tracks. The present study has suggested that the transport of a nucleoplasmic protein may also occur on distinct nuclear pathways.
authors.affiliation: Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38101-0318.
authors.forename: K G
authors.initials: KG
authors.lastname: Murti
authors.forename: P S
authors.initials: PS
authors.lastname: Brown
authors.forename: L
authors.initials: L
authors.lastname: Ratner
authors.forename: J V
authors.initials: JV
authors.lastname: Garcia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D015704:CD4 Antigens / Q000378:metabolism*; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism / Q000382:microbiology* / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D015693:Gene Products, nef / Q000032:analysis* / Q000096:biosynthesis; D015754:Genes, nef; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008099:Liver / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000382:microbiology*; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015704:CD4 Antigens; D015693:Gene Products, nef; C075564:NOLC1 protein, human; C513067:Nolc1 protein, rat; D009687:Nuclear Proteins; D010750:Phosphoproteins; D054311:nef Gene Products, Human Immunodeficiency Virus