Identification of a cellular protein that specifically interacts with the essential cysteine region of the HIV-1 tat transactivator
Identification of a cellular protein that specifically interacts with the essential cysteine region of the HIV-1 tat transactivator
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DOI：
10.1006/viro.1996.0071
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发表时间：
1996-02-15
期刊：
影响因子：
3.7
通讯作者：
Chinnadurai, G
中科院分区：
文献类型：
--
作者：
Kamine, J;Elangovan, B;Chinnadurai, G
人类免疫缺陷病毒（HIV）的Tat蛋白是一种强大的HIV基因表达激活剂。遗传和生化证据表明，一种或多种细胞辅助因子可能对Tat活性起重要作用。我们在酵母中使用双杂交相互作用克隆技术，从人类b淋巴母细胞文库中鉴定出一个部分cDNA克隆（克隆10），该克隆特异性地与HIV-1 Tat的n端31个氨基酸相互作用，其中包含Tat激活域必需的富含半胱氨酸的部分。编码的蛋白也能在体外与纯化的Tat结合。Tat中单个必需半胱氨酸残基的突变消除了Tat与克隆10之间的相互作用，表明与编码蛋白的相互作用对Tat的活性很重要。我们已经鉴定出Tat结合蛋白的全长cDNA，并表明编码蛋白Tip60 （Tat相互作用蛋白，60 kDa）的过表达在瞬时表达试验中导致HIV-1启动子的Tar反激活增加四倍，而不增加HIV启动子的基础活性或激活异源RSV启动子。这些数据连同遗传和体外结合数据支持了Tip60可能是Tat的辅助因子参与HIV基因表达调控的观点。(C) 1996学术出版社，Inc.
The Tat protein of the human immunodeficiency virus (HIV) is a powerful activator of HIV gene expression. Genetic and biochemical evidence suggests that one or more cellular cofactors may be important for Tat activity. We have used two-hybrid interactive cloning in yeast to identify a partial cDNA clone (clone 10) from a human B-lymphoblastoid library that specifically interacts with the N-terminal 31 amino acids of HIV-1 Tat which contains the essential cysteine-rich portion of the Tat activation domain. The encoded protein also binds to purified Tat in vitro. Mutation of single essential cysteine residues in Tat abolishes interaction between Tat and clone 10, suggesting that interaction with the encoded protein is important for Tat activity. We have identified the full-length cDNA for the Tat binding protein and shown that overexpression of the encoded protein, Tip60 (Tat interactive protein, 60 kDa), results in a fourfold augmentation of Tar transactivation of the HIV-1 promoter in transient expression assays without increasing the basal activity of the HIV promoter or activating the heterologous RSV promoter. These data together with the genetic and in vitro binding data support the notion that Tip60 might be a cofactor of Tat involved in the regulation of HIV gene expression. (C) 1996 Academic Press, Inc.