Characterization of a novel nuclear localization signal in the HTLV-I tax transactivator protein.
The Tax trans-activator protein of the type I human T-cell leukemia virus is expressed predominantly in the nuclei of cells. However, this viral trans-activator is distinguished from most other nuclear proteins by the absence of a short highly basic nuclear localization signal. Previous mutational analyses of the tax gene revealed that many of the missense mutations involving the amino terminus of Tax resulted in a predominantly cytoplasmic pattern of expression. We now report that the amino terminal 48 residues of Tax comprise a functional nuclear localization signal as demonstrated by the ability of this region to retarget expression of a large cytoplasmic protein to the nucleus.
Smith
M R
MR
Howard Hughes Medical Institute, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
Greene
W C
WC
D000595:Amino Acid Sequence; D001483:Base Sequence; D004252:DNA Mutational Analysis; D016356:Gene Products, tax / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D016356:Gene Products, tax; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase