Transcriptional regulation is affected by subnuclear targeting of reporter plasmids to PML nuclear bodies
Transcriptional regulation is affected by subnuclear targeting of reporter plasmids to PML nuclear bodies
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DOI：
10.1128/mcb.00636-06
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发表时间：
2006-12-01
影响因子：
5.3
通讯作者：
Bazett-Jones, David P.
中科院分区：
文献类型：
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作者：
Block, Gregory J.;Eskiw, Christopher H.;Bazett-Jones, David P.
尽管 PML 蛋白已被报道具有转录共激活因子和辅抑制因子潜力，但 PML 核体 (PML NB) 本身对转录调节的贡献尚不清楚。在这里，我们证明人工连接到 PML 或 Sp100 的 PML NB 靶向结构域的质粒 DNA 优先定位于 PML NB。使用束缚技术，我们将猿猴病毒 40 启动子驱动的荧光素酶报告质粒靶向 PML NB，从而抑制转基因转录活性。相反，含有巨细胞病毒启动子的报道质粒的束缚导致激活。靶向最小真核启动子并不影响其活性。可以通过改变 PML NB 成分（包括 Sp100 和 PML 蛋白亚型）的细胞浓度来调节靶向启动子的表达。最后，我们证明了 ICP0（混杂的单纯疱疹病毒反式激活因子）可以提高与 PML NB 相连的质粒 DNA 的转录激活水平。我们得出的结论是，当 PML NB 成分人工连接到报告质粒上时，PML NB 有助于以启动子依赖性方式调节连接的 DNA。我们的研究结果表明，瞬时转录测定对转基因质粒的亚核定位敏感。
Whereas the PML protein has been reported to have both transcriptional coactivator and corepressor potential, the contribution of the PML nuclear body (PML NB) itself to transcriptional regulation is not well understood. Here we demonstrate that plasmid DNA artificially tethered to PML or the PML NB-targeting domain of Sp100 is preferentially localized to PML NBs. Using the tethering technique, we targeted a simian virus 40 promoter-driven luciferase reporter plasmid to PML NBs, resulting in the repression of the transgene transcriptional activity. Conversely, the tethering of a cytomegalovirus promoter-containing reporter plasmid resulted in activation. Targeting a minimal eukaryotic promoter did not affect its activity. The expression of targeted promoters could be modulated by altering the cellular concentration of PML NB components, including Sp100 and isoforms of the PML protein. Finally, we demonstrate that ICP0, the promiscuous herpes simplex virus transactivator, increases the level of transcriptional activation of plasmid DNA tethered to the PML NB. We conclude that when PML NB components are artificially tethered to reporter plasmids, the PML NB contributes to the regulation of the tethered DNA in a promoter-dependent manner. Our findings demonstrate that transient transcription assays are sensitive to the subnuclear localization of the transgene plasmid.