The NFY transcription factor functions as a repressor and activator of the von Willebrand factor promoter
The NFY transcription factor functions as a repressor and activator of the von Willebrand factor promoter
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DOI：
10.1182/blood.v99.7.2408
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发表时间：
2002-04-01
期刊：
影响因子：
20.3
通讯作者：
Jahroudi, N
中科院分区：
文献类型：
--
作者：
Peng, YW;Jahroudi, N
人血管性血友病因子（VWF）基因序列-487至+247在体外起内皮特异性启动子的作用。VWF启动子的激活机制的分析导致了一些顺式作用元件和反式作用因子，调节其活性的鉴定。显示加塔和Ets转录因子作为转录激活因子起作用，而显示NF 1和Octl抑制转录。我们已经报道了在外显子1中存在另一个阻遏元件，该元件与命名为“R”的蛋白质复合物相互作用。在没有NF 1结合的情况下，这种相互作用的抑制导致非内皮细胞中的启动子激活。我们现在已经鉴定了“R”蛋白复合物为NFY转录因子。使用DNA甲基化干扰试验和碱基置换突变分析，我们表明，NFY与VWF启动子中的核苷酸+226至+234对应的新DNA序列相互作用，该序列不符合共有NFY结合序列CCAAT。VWF基因确实含有一个CCAAT元件，位于TATA盒的下游，我们发现NFY因子也与这个CCAAT元件相互作用。使用针对NFY的A、B和C亚基的特异性抗体，我们证明了与CCAAT序列相互作用的NFY复合物具有与第一外显子序列结合的阻遏物类似的组成。突变分析和转染研究的结果表明，NFY与上游CCAAT元件的相互作用是VWF启动子激活所必需的。基于这些结果，我们推测NFY既可以作为转录抑制因子又可以作为转录激活因子，其功能可能通过其DNA结合序列来调节。(C)2002年，美国血液学会。
Human von Willebrand factor (VWF) gene sequences -487 to +247 function as an endothelial-specific promoter in vitro. Analysis of the activation mechanism of the VWF promoter has resulted in the identification of a number of cis-acting elements and trans-acting factors that regulate its activity. The GATA and Ets transcription factors were shown to function as activators of transcription, whereas NF1 and Octl were shown to repress transcription. We have reported the presence of another repressor element in exon 1 that interacted with a protein complex designated "R." In the absence of NF1 binding, inhibition of this interaction resulted in promoter activation in nonendothelial cells. We have now identified the "R" protein complex as the NFY transcription factor. Using DNA methylation interference assay and base substitution mutation analysis, we show that NFY interacts with a novel DNA sequence corresponding to nucleotides +226 to +234 in the VWF promoter that does not conform to the consensus NFY binding sequence CCAAT. The VWF gene does contain a CCAAT element that is located downstream of the TATA box and we show that the NFY factor also interacts with this CCAAT element. Using antibodies specific against the A, B, and C subunits of NFY, we demonstrate that the NFY complexes interacting with the CCAAT sequence have a composition similar to that of the repressor binding to the first exon sequences. The results of mutation analysis and transfection studies demonstrated that the interaction of NFY with the upstream CCAAT element is required for VWF promoter activation. Based on these results, we hypothesize that NFY can function both as a repressor and activator of transcription and Its function may be modulated through its DNA binding sequences.(C) 2002 by The American Society of Hematology.