Factors Influencing Genetic Transcription Initiation And

RNA形成部分的研究旨在理解和利用细胞DNA复制过程，HIV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是参与去除RNA-DNA杂合体的RNA的重要酶，并且在该病毒的RNA基因组转化为DNA期间，与细胞中的DNA复制和HIV复制密切相关。细胞的RNA酶H和HIV共享利用类似蛋白质结构切割RNA的共同酶机制。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RNases H的表达可以增强药物的疗效。在这些努力中采用分子遗传学、生物化学和小鼠动物模型。 在转录过程中，RNA/DNA杂合体可以形成，并且通常被RNase H切割。与Marc Drolet博士一起，我们报告说，当蛋白质合成受阻时，细菌中RNA/DNA杂交体形成（R环）增加，从而释放新生RNA，在转录后立即与DNA退火。在真核生物中，已经报道了类似的观察结果，并且增加RNase H1的水平可以消除由于未能去除R环的RNA而产生的一些问题。我们现在知道，真核生物的RNA酶H比细菌的酶更复杂，并且小鼠RNA酶H1（以及可能的其他真核生物的RNA酶H1）的酶活性在与RNA/DNA杂合体结合时形成复合物，使得该酶在降解某些类型的RNA/DNA杂合体时更有效。我们与NCI- Frederick的研究小组合作，一直在研究RNase H的抑制剂，这些抑制剂可能被证明在HIV-AIDS治疗中有用。从我们早期的工作表明，小鼠RNase H1对发育至关重要，我们知道，重要的是要有专门针对艾滋病毒-艾滋病RNase H而不是细胞酶的药物。潜在药物的筛选现在包括使用我们实验室分离的人类RNase H1。

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.