CARCINOGENS AND CHROMATIN STRUCTURE AND FUNCTION

描述：这是一份曾经修改过的提案，延续了斯莫森博士的 为了实现这一目标，提出了对三个目标的研究。 第一部分的结构是试图阐明 染色质DNA断裂的PADPRP。初步研究将评估 修复过程中DNA末端和末端的PADPRP循环，使用 细菌表达的PADPRP突变蛋白。另外，使用稳定的 转染同步的3T3-L1细胞，将寻找证据 通过以下方式确定PADPRP在DNA复制/修复中的直接作用 也确定了与DNA聚合酶α的物理联系 作为一种多酶DNA复制复合体。PADPRP的切割 在此系统中也将对细胞凋亡进行评估。AIM II是 旨在确定聚(ADP-核糖)信号是否产生 在DNA链断裂之后，在 P53蛋白的积聚和细胞停滞在G1期直到修复 就可以继续了。在目标III中，PADPRP在V(D)J中的机制作用 重组，它与链断裂有几个相同的酶特性 在修复过程中重新连接，将进行探索。经济衰退带来的影响 中将研究此过程中的PADPRP表达式构造 表达RAG-1和RAG-2基因的小鼠3T3细胞 通过使用新建立的“基因敲除”小鼠对整个动物进行研究。

DESCRIPTION: This is a once-amended proposal to continue Dr. Smulson's studies into Three aims are proposed to pursue this objective. The first is structured to attempt to clarify the interaction of PADPRP with DNA breaks in chromatin. Initial studies will evaluate the cycling of PADPRP on and off ends of DNA during repair, using bacterially-expressed PADPRP mutant proteins. Also, using stably transfected synchronized 3T3-L1 cells, evidence will be sought to establish the direct role of PADPRP with DNA replication/repair by defining the physical association with DNA polymerase alpha, as well as a multi-enzyme DNA replicative complex. The cleavage of PADPRP during apoptosis in this system also will be evaluated. Aim II is designed to determine whether the poly(ADP-ribose) signal generated subsequent to DNA strand breaks plays a significant role in the accumulation of p53 protein and the arrest of cells at G1 until repair can proceed. In aim III the mechanistic role of PADPRP in V(D)J recombination, which shares several enzymatic features with strand break rejoining during repair, will be explored. The effects of the PADPRP expression constructs on this process will be examined in mouse 3T3 cells expressing the RAG 1 and RAG 2 genes and in the context of the whole animal by use of newly-established "knockout" mice.