INCREASED CELLULAR UPTAKE OF THE HUMAN IMMUNODEFICIENCY VIRUS-1 TAT PROTEIN AFTER MODIFICATION WITH BIOTIN
INCREASED CELLULAR UPTAKE OF THE HUMAN IMMUNODEFICIENCY VIRUS-1 TAT PROTEIN AFTER MODIFICATION WITH BIOTIN
复制标题
DOI：
10.1006/abio.1995.1267
复制
发表时间：
1995-05-01
影响因子：
2.9
通讯作者：
PEPINSKY, B
中科院分区：
文献类型：
--
作者：
CHEN, LL;FRANKEL, AD;PEPINSKY, B
当外源添加到组织培养物中时，人类免疫缺陷病毒-1 Tat蛋白可以有效地进入细胞。使用 Tat 的反式激活活性作为细胞内递送的量度，我们发现向 Tat 添加疏水基团可增强其摄取。生物素是测试的试剂中最有前途的，我们更详细地描述了这种效应。当通过半胱氨酸硫醇偶联时，向 Tat 添加单一生物素可将活性提高约六倍。仅在可还原的生物素类似物中才观察到活性增加，因为已知用不可裂解的类似物进行修饰可阻断 Tat 反式激活活性。当与未经交联的 Tat 混合时，生物素对 Tat 的吸收没有影响。最近，Tat 被用作引导异源蛋白质摄取到细胞中的载体。我们使用 RNase 作为研究 Tat 介导的摄取的模型系统，发现生物素还增加了 Tat(37-58)-RNase 缀合物的递送。通过添加疏水基团增加对 Tat 和 Tat 缀合物的吸收可能会显着增强 Tat 作为递送载体的有用性，并且该方法可能适用于其他系统。 (C) 1995 学术出版社
The human immunodeficiency virus-1 Tat protein can efficiently enter cells when added exogenously in tissue culture. Using the transactivation activity of Tat as a measure of intracellular delivery, we found that the addition of hydrophobic groups to Tat potentiated its uptake. Biotin was the most promising of the reagents tested and we characterized this effect in more detail. When coupled through a cysteine thiol, the addition of a single biotin to Tat increased activity by about sixfold. Increased activity was only seen with reducible biotin analogs, as modification with noncleavable analogs is known to block Tat transactivation activity. Biotin had no effect on Tat uptake when mixed with Tat without cross-linking. Recently, Tat was used as a carrier to direct the uptake of heterologous proteins into cells. We have used RNase as a model system for studying Tat-mediated uptake and found that biotin also increased the delivery of a Tat(37-58)-RNase conjugate. The increased uptake of Tat and Tat conjugates by addition of hydrophobic groups may significantly enhance the usefulness of Tat as a delivery vehicle, and the approach may be applicable to other systems. (C) 1995 Academic Press, Inc.