Braddock M, Chambers A, Wilson W, Esnouf M P, Adams S E, Kingsman A J, Kingsman S M
Virus Molecular Biology Group Department of Biochemistry, Oxford, England.
Cell. 1989 Jul 28;58(2):269-79. doi: 10.1016/0092-8674(89)90841-6.
Replication of the human immunodeficiency virus (HIV-1) depends upon the viral TAT protein. TAT stimulates gene expression via a target response sequence (TAR) located within the HIV-1 LTR. As TAR is located in the transcribed region it could act as a signal in either the DNA, the RNA, or both. To test whether TAT acts on transcription and/or posttranscriptionally, we produced TAT in yeast and monitored its activity after microinjection into the nucleus or cytoplasm of Xenopus oocytes. The TAT protein stimulated TAR-dependent expression, but this activation was not inhibited by transcriptional inhibitors. Furthermore, TAR-containing RNA, produced in vitro, was "activated" by TAT after coinjection into oocytes. This activation only occurred, however, when the RNA was injected into the nucleus and not into the cytoplasm. Our data indicate, therefore, that in the Xenopus system TAT acts on presynthesized RNA and that the nucleus is involved in this action.
人类免疫缺陷病毒（HIV-1）的复制依赖于病毒TAT蛋白。TAT通过位于HIV-1长末端重复序列（LTR）内的靶反应序列（TAR）刺激基因表达。由于TAR位于转录区域，它可以在DNA、RNA或两者中充当信号。为了测试TAT是在转录水平还是转录后水平起作用，我们在酵母中产生TAT，并在显微注射到非洲爪蟾卵母细胞的细胞核或细胞质后监测其活性。TAT蛋白刺激了TAR依赖的表达，但这种激活不受转录抑制剂的抑制。此外，体外产生的含TAR的RNA在与TAT共同注射到卵母细胞后被“激活”。然而，这种激活只在RNA被注射到细胞核而不是细胞质时才会发生。因此，我们的数据表明，在非洲爪蟾系统中，TAT作用于预先合成的RNA，并且细胞核参与了这一作用。
