KINETOPLAST DNA ASSOCIATED PROTEINS IN KINETOPLASTID PROTOZOA

动质体目的成员，包括锥体和锥体 利什曼原虫，分享最不寻常的线粒体DNA结构之一 发现于自然界。线粒体存在于这些生物体中的单个线粒体 含有相对较大比例的细胞DNA(动泡体 DNA，kDNA)组织成盘状结构，由 两种拓扑相连的环状分子的布居。 尽管我们最近在理解上取得了进展 网络的主要DNA成分的复制机制， 关于kDNA结构和功能的几个突出问题 网络仍无人接听。例如，目前还不清楚 线粒体功能网络结构所服务的，也不是它是如何服务的 在复制结束时分区。维护以及可能的 KDNA的功能可能取决于细胞内的某些蛋白质成分 网络。我们对克氏锥虫的初步研究表明 几种蛋白质在暴露后仍与kDNA网络相关 在2M的氯化钠存在下，将锥虫细胞置于温和的洗涤剂中。 针对这些克氏锥虫kDNA-蛋白复合体的兔抗体 识别一些似乎与超级螺旋结合的蛋白质(S) 克鲁兹毛滴虫微环DNA的形式。更有趣的是，同时使用 免疫荧光和免疫电子显微镜观察到 相同的抗体制剂与存在的动泡体DNA发生交叉反应。 在相关的动质体原生动物中。基于这些观察， 目前的研究方案旨在揭示一些基本特征 关于动泡体DNA网络的结构和功能， 研究一些与之相关的蛋白质的功能 KDNA。 我们建议首先，鉴定和表征结合到 克鲁兹微环；第二，鉴定常见的与kDNA相关的 存在于kDNA网络制剂中的蛋白质(KAP) 动质原生动物；第三，分离和克隆基因 对选定的KAP进行编码。 通过了解kDNA相关蛋白的结构和功能 我们可能会学到很多关于kDNA网络是如何维护和 传播了。这些信息也可能为我们提供一个更理性的 彻底根除这些寄生虫的方法，其中一些 它们是几种重要的人类疾病的病原体。

Members of the order Kinetoplastida, which include trypanosomes and leishmania, share one of the most unusual mitochondrial DNA structures found in nature. The single mitochondria present in these organisms contains a relatively large proportion of the cellular DNA (kinetoplast DNA, kDNA) organized in a disk-shaped structure and made up of a population of two types of topologically linked circular molecules. In spite of the recent advances made in our understanding of the mechanism of replication of the major DNA component of the networks, some outstanding questions about the structure and function of kDNA networks still remain unanswered. For example, it is not clear what mitochondrial function the network structure serves, nor how it is partitioned at the end of replication. The maintenance and possibly the function of kDNA may depend on some proteins components of the networks. Our preliminary studies with Trypanosoma cruzi indicate that several proteins remain associated with kDNA networks after exposure of trypanosome cells to a mild detergent in presence of 2M NaCl. Rabbit antibodies raised against these T.cruzi kDNA-protein complexes recognize some protein(s) that appear to be bound to the supercoiled form of T.cruzi minicircle DNA. More interestingly, using both immunofluorescence and immunoelectron microscopy, we have observed that the same antibody preparation cross-reacts with kinetoplast DNA present in related kinetoplastid protozoa. Based on these observations, the present research proposal is designed to unravel some basic features about the structure and function of kinetoplast DNA networks, by investigating the function of some of the proteins associated with kDNA. We propose first, to identify and characterize proteins bound to T.cruzi minicircles; second, to identify common kDNA-associated proteins (KAPs) present in kDNA network preparations from other kinetoplastid protozoa; and third, to isolate and clone the genes encoding for selected KAPs. By understanding the structure and function of kDNA-associated proteins we may learn a great deal about how kDNA networks are maintained and propagated. This information may also provide us with a more rational approach toward the complete eradication of these parasites, some of which are the causative agents of several important human diseases.