Biology of Topoisomerase 1 in S Cerevisiae

描述(由申请人提供)：本提案的目的是了解 一种新的DNA聚合酶Pol K是如何连接复制叉通道的 在新形成的姐妹染色单体之间建立凝聚力。我们有 最近确定PO1 K(由TRF4和TRF5编码)对两者都是必需的 复制与凝聚(Wang等人(2000)科学289,774-779)。这些 观察打开了进一步机械性洞察凝聚力的大门 建立完成，它是如何耦合到复制分叉通道的 也可能与姐妹染色单体之间的键的性质有关。这一机制 在复制过程中形成凝聚力的方式对维护至关重要 基因组的完整性，但仍然是一个根本的悬而未决的问题 在细胞生物学中。我们假设POI K是 真核生物中的复制叉子，其功能是复制凝聚力 因此，在染色单体之间建立粘连状态。 我们进一步假设PO1K和非聚合酶之间的相互作用 PolE的C-末端结构域发生，并且这种相互作用是必要的 FOPOL K作为S相检查点传感器。旨在测试 我们的假设概述如下。

DESCRIPTION (provided by applicant): The goal of this proposal is to understand how a novel DNA polymerase, Pol K, functions to couple replication fork passage to establishment of cohesion between newly formed sister chromatids. We have recently determined that po1 K (encoded by TRF4 and TRF5) is essential for both replication and cohesion (Wang et al. (2000) Science 289, 774-779). These observations open the door to further mechanistic insight into how cohesion establishment is accomplished, how it is coupled to replication fork passage and perhaps to the nature of the bond between sister chromatids. The mechanism by which cohesion is formed during replication is crucial for the maintenance of genomic integrity, but nonetheless remains a fundamental unanswered question in cell biology. We hypothesize that POI K is an essential component of the replication fork in all eukaryotes whose function is to replicate cohesion sites specifically and, thereby, set up the cohesed state between chromatids. We further hypothesize that an interaction between po1 K and the non-polymerase C-terminal domain of pol E about occurs and that this interactions is necessary forpol K to act as an S-phase checkpoint sensor. Experiments designed to test our hypothesis are outlined below.