Factors Influencing Genetic Transcription Initiation And

RNA形成部分的研究旨在了解和利用细胞DNA复制所涉及的过程，艾滋病毒复制与这些细胞事件的关系，以及如何将这些信息用于治疗目的。我们正在研究在DNA复制或转录过程中形成的RNA-DNA杂交体的形成和分解。核糖核酸酶H是参与RNA-DNA杂交物RNA去除的重要酶，与细胞内DNA复制和HIV病毒基因组向DNA转化过程中的复制密切相关。细胞的RNase H和HIV共享共同的酶机制，即利用相似的蛋白质结构裂解RNA。改变特定疾病相关基因水平的药物正在开发中，以利用细胞内的RNase H。调节RNase H的表达可增强药物的疗效。分子遗传学、生物化学和小鼠动物模型被用于这些努力。 在转录过程中，RNA/DNA杂交体可以形成并通常被RNaseH切割。我们与Marc Drolet博士一起报道，当蛋白质合成受阻时，细菌中RNA/DNA杂交体的形成(R-环)会增加，从而在转录后立即释放新生的RNA与DNA结合。在真核生物中，也有类似的观察到，增加RNaseH1的水平可以消除由于未能移除R环的RNA而造成的一些问题。我们现在知道，真核RNase H比细菌酶更复杂，小鼠RNase H1(可能还有其他真核RNase H1)的酶活性在与RNA/DNA杂化时形成一个复合体，使该酶在降解Ceratin类型的RNA/DNA杂交物时更有效。与NCI-Frederick的团队合作，我们一直在研究RNases H的抑制剂，这些抑制剂可能被证明在艾滋病毒-艾滋病治疗中有用。从我们早期的工作表明小鼠RNaseH1对发育至关重要，我们知道有专门针对HIV-AIDS RNaseH而不是细胞酶的药物是重要的。潜在药物的筛选现在包括使用在我们实验室分离的人RNaseH1。

Research in the Section on Formation of RNA is directed toward understanding and utilization of processes involved in cellular DNA replication, the relationship of HIV replication to these cellular events, and how to use this information for therapeutic purposes. We are examining the formation and resolution of RNA-DNA hybrids formed during DNA replication or transcription. Ribonucleases H are important enzymes participating in removal of the RNA of the RNA-DNA hybrids and are intimately related to DNA replication in cells and in HIV replication, during the conversion of the RNA genome of this virus to DNA. RNases H of cells and HIV share common enzymatic mechanisms of cleavage of RNA utilizing similar protein architectures. Drugs to alter levels of specific disease-related genes are being developed to take advantage of RNases H within the cell. Regulated expression of RNases H could enhance the efficacy of the drugs. Molecular genetic, biochemical, and mouse animal models are employed in these efforts. During transcription, RNA/DNA hybrids can form and are usually cleaved by RNase H. Together with Dr. Marc Drolet, we have reported that an increase in RNA/DNA hybrid formation (R-loops) occurs in bacteria when protein synthesis is blocked, thereby freeing to nascent RNA to anneal to the DNA immediately after transcription. In eukaryotes, a similar observation has been reported and that increasing the level of RNase H1 can eliminate some of the problems created by failure to remove the RNA of R-loops. We now know that the eukaryotic RNases H are more complex than the bacterial enzymes, and that the enzymatic activity of mouse RNase H1 (and presumably other eukaryotic RNases H1) form a complex when binding to and RNA/DNA hybrid that enables the enzyme to be more efficient when degrading ceratin types of RNA/DNA hybrids. In collaboration with the groups at NCI- Frederick we have been examining inhibitors of RNases H that could prove useful in HIV-AIDS therapy. From our earlier work showing that the mouse RNase H1 is critical for development, we know that it is important to have drugs that specifically target the HIV-AIDS RNase H not the cellular enzyme. Screening of potential drugs now includes use of the human RNase H1 isolated in our laboratory.