Molecular determinants for cellular uptake of Tat protein of human immunodeficiency virus type 1 in brain cells
Molecular determinants for cellular uptake of Tat protein of human immunodeficiency virus type 1 in brain cells
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DOI：
10.1128/jvi.71.3.2495-2499.1997
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发表时间：
1997-03-01
影响因子：
5.4
通讯作者：
Nath, A
中科院分区：
文献类型：
--
作者：
Ma, MH;Nath, A
我们测定了人胎儿星形胶质细胞、神经母细胞瘤细胞和胎儿神经元对(125)标记的全长TAT(氨基酸1-86)(I-125-TAT(1-86))和I-125-TAT(1-72)(第一外显子)的摄取，发现不含第二外显子的I-125-TAT(1-72)的摄取明显低于I-125-TAT(1-86)的摄取(P<；0.01)。这表明TAT的C-末端区域在其细胞摄取中起着重要作用。I-125-TAT的摄取可被硫酸葡聚糖抑制，被未标记的TAT竞争性抑制，但不被重叠的15聚体多肽所抑制，这表明TAT的内化是电荷和构象依赖的。有趣的是，其中一个15肽，TAT(28-42)，极大地提高了I-125-TAT的摄取。这些发现对于理解人类免疫缺陷病毒1型感染的神经发病机制以及TAT在药物输送到细胞中的潜在应用具有重要意义。
We measured the cellular uptake of (125)-labeled full-length Tat (amino acids 1 to 86) (I-125-Tat(1-86)) and I-125-Tat(1-72) (first exon) in human fetal astrocytes, neuroblastoma cells, and human fetal neurons and demonstrated that the uptake of I-125-Tat(1-72) without the second exon,vas much lower than that of I-125-Tat(1-86) (P < 0.01). This suggests an important role for the C-terminal region of Tat for its cellular uptake. I-125-Tat uptake could be inhibited by dextran sulfate and competitively inhibited by unlabeled Tat but not by overlapping 15-mer peptides, suggesting that Tat internalization is charge and conformationally dependent. Interestingly, one of 15-mer peptides, Tat(28-42), greatly enhanced I-125-Tat uptake. These findings are important for understanding the neuropathogenesis of human immunodeficiency virus type 1 infection and in the potential application of Tat for drug delivery to cells.