title: Effects of a highly basic region of human immunodeficiency virus Tat protein on nucleolar localization.
abstract: Human immunodeficiency virus type 1 encodes a positive trans-activator protein, Tat, which is located predominantly in the cell nucleolus. To study the role of the basic region of Tat in nucleolar localization, we constructed fusion genes encoding serially deleted segments of Tat joined to the amino-terminal end of the Escherichia coli beta-galactosidase molecule. We show that the basic region of Tat was sufficient for nuclear localization but not for nucleolar localization. Addition of three amino acids (59, 60, and 61) of the Tat sequence at the C-terminal end of the basic region was necessary for the chimeric beta-galactosidase to localize in the nucleus as well as in the nucleolus. We demonstrate that a short amino acid sequence (G-48 RKKRRQRRRA HQ N-61), when fused to the amino terminus of beta-galactosidase, can act as a nucleolar localization signal.
authors.affiliation: Institute for Virus Research, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Siomi
authors.forename: H
authors.initials: H
authors.lastname: Shida
authors.forename: M
authors.initials: M
authors.lastname: Maki
authors.forename: M
authors.initials: M
authors.lastname: Hatanaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002466:Cell Nucleolus / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015696:Gene Products, tat / Q000378:metabolism*; D015497:HIV-1; D007763:Lac Operon; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D001616:beta-Galactosidase / Q000235:genetics; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015696:Gene Products, tat; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D054322:tat Gene Products, Human Immunodeficiency Virus; D001616:beta-Galactosidase