Effect of HIV type 1 Tat protein on butyric acid-induced differentiation in a hematopoietic progenitor cell line.
Effect of HIV type 1 Tat protein on butyric acid-induced differentiation in a hematopoietic progenitor cell line.
复制标题
HIV 1 型 Tat 蛋白对丁酸诱导的造血祖细胞系分化的影响。
DOI：
10.1089/aid.1996.12.1529
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Agrawal,KC
中科院分区：
文献类型：
--
作者：
Mondal,D;Agrawal,KC
Thetrans-activator protein (Tat) of HIV-1 plays an important role in viral pathogenesis. Since Tat has been shown to alter expression of a number of host cellular genes, we have investigated the role of Tat in modulating gene expression and differentiation in hematopoietic progenitor cells. Tat protein was introduced in K562 cells, a human hematopoietic progenitor cell line, by either scrape-loading onto HeLa (HL)-tatcells or direct electroporation of an affinity-purified glutathioneS-transferase (GST)-Tat fusion protein. Under these conditions, butyric acid-induced hemoglobin production in K562 cells was suppressed by 65 and 52%, respectively. However, coculturing with wild-type HeLa cells or electroporation with the control GST protein did not decrease hemoglobin production. To confirm the presence of bioactive Tat protein within K562 cells, the cells were transiently transfected with a pHIV/LTR-CAT prior to the introduction of Tat. A 30- to 40-fold induction in CAT gene expression was observed in the transfected K562 cells, which were either cocultured with HL-tator were electroporated with GST-Tat. Simultaneous transient transfection of K562 cells with a TAR expression plasmid, to compete for the availability of Tat protein, significantly downregulated the HIV LTRtrans-activation by Tat. In addition, overexpression of the TAR RNAs in K562 cells was able to downregulate the suppressive effect of Tat on butyric acid-induced differentiation. RT-PCR analysis of the total RNAs isolated from these cells demonstrated that Tat protein suppressed the butyric acid-induced γ-globin gene expression by an average of 54% without affecting the level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNAs. These data indicate that the viral Tat protein plays a significant role in abrogating erythroid differentiation in K562 cells.
