Green M, Loewenstein P M
Institute for Molecular Virology, St. Louis University School of Medicine, Missouri 63110.
Cell. 1988 Dec 23;55(6):1179-88. doi: 10.1016/0092-8674(88)90262-0.
HIV-1 encodes a potent trans-activator protein, tat, which is essential for viral gene expression. To study tat domains that function in trans-activation, we chemically synthesized the 86 amino acid tat protein (tat-86) and tat mutant peptides. Remarkably, tat-86 is rapidly taken up by cells, and produces a massive and specific stimulation of HIV-LTR-driven RNA synthesis. Mutant peptides of 21 to 41 amino acids exhibit significant activity. Only two regions are essential for trans-activation; we suggest that one represents an activation region and the other, a nucleic acid binding or nuclear targeting region. Amino acid substitutions within these regions greatly reduce trans-activation, demonstrating the functional significance of these domains. The N-terminal 37 amino acids and exon 2 are not essential. Thus, tat is similar to regulatory proteins of Ad E1A and BPV1 E5 oncogenes, requiring only small domains for autonomous function.
HIV-1编码一种强效反式激活蛋白tat，它对于病毒基因表达至关重要。为了研究在反式激活中起作用的tat结构域，我们化学合成了86个氨基酸的tat蛋白（tat-86）和tat突变肽。值得注意的是，tat-86能迅速被细胞摄取，并对HIV-LTR驱动的RNA合成产生大量且特异性的刺激。21至41个氨基酸的突变肽表现出显著活性。只有两个区域对于反式激活是必不可少的；我们认为一个代表激活区域，另一个代表核酸结合或核靶向区域。这些区域内的氨基酸取代会大大降低反式激活，证明了这些结构域的功能重要性。N端的37个氨基酸和外显子2并非必不可少。因此，tat类似于腺病毒E1A和牛乳头瘤病毒1型E5癌基因的调节蛋白，仅需要小的结构域就能自主发挥功能。
