Nuclear preservation and cytoplasmic degradation of human immunodeficiency virus type 1 Rev protein.
Rev, a major regulatory protein of human immunodeficiency virus type 1, has been demonstrated to shuttle between the nucleus and cytoplasm of infected cells. The fate of the Rev protein in living cells was evaluated by pulse-chase experiments using a transient Rev expression system. Sixteen hours after chasing with unlabelled amino acids, 45% of the labelled Rev was still present, which clearly indicates a long half-life of Rev in living cells. A Rev mutant which is deficient in the ability to migrate from the nucleus to the cytoplasm was degraded more slowly than the wild-type Rev protein. As well, another Rev mutant protein, which lacks a functional nucleolar targeting signal (NOS) and is unable to enter the cell nucleus, was rapidly degraded and undetectable 16 h after chasing. Nuclear-nucleolar targeting properties provided by a divergent NOS from a related retrovirus, which was used to substitute for the NOS of Rev, increased the intracellular half-life of this Rev mutant. Moreover, coexpression of an intracellular anti-Rev single-chain antibody (SFv), which has been shown to interfere with the nuclear translocation of Rev, accelerated the degradation of the wild-type Rev protein. Differential degradation of Rev in the nucleus and cytoplasm may play a critical role in determining and maintaining different stages of human immunodeficiency virus type 1 infection, in conjunction with the shuttling properties of the Rev protein.
Kubota
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S
Dorrance H. Hamilton Laboratories, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Duan
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Furuta
R A
RA
Hatanaka
M
M
Pomerantz
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015694:Gene Products, rev / Q000378:metabolism*; D016370:Gene Products, rex / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism*; D006207:Half-Life; D006801:Humans; D007135:Immunoglobulin Variable Region; D008969:Molecular Sequence Data; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D054321:rev Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D015694:Gene Products, rev; D016370:Gene Products, rex; D007135:Immunoglobulin Variable Region; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; C092667:anti-HIV-1 Rev SFv; D054321:rev Gene Products, Human Immunodeficiency Virus