Significance of the novel Bok-IP3 receptor interaction

肌醇1，4，5-三磷酸受体（Inositol 1，4，5-trisphosphate receptor，IP 3Rs）在脊椎动物细胞内信号转导中起着重要作用。 它们是一个由三种非常相似的蛋白质组成的家族，在内质网中形成四聚体Ca 2+通道 (ER)膜。在过去的二十年里，我一直在研究IP 3R的分子生物学， 发现Bok是一种非常不为人所知的Bcl-2蛋白家族成员，具有独特的功能， 对IP 3R的要求很高Bcl-2蛋白家族控制着内源性凋亡途径， 研究，无论是从基本的细胞生物学的角度来看，并作为抗癌药物的目标。博克是最 类似于已充分表征的促凋亡蛋白Bax和巴克，但其细胞作用仍然是谜， 然而，共识是，Bok定位于ER膜，并在以下方面发挥作用： 凋亡信号在过去的3年里，我的实验室已经开始表征新的Bok-IP 3R相互作用 及其意义，但仍有许多工作要做。现在，通过三个具体目标，我计划测试 假设Bok与IP 3R的结合调节IP 3R功能，并且是Bok在以下方面发挥作用所必需的： 细胞凋亡，严重依赖于新开发的细胞系，其中Bok已经使用CRISPR/Cas9- 基于方法。 目标1。IP 3R 1上Bok结合位点的解析和结合缺陷型IP 3R 1的开发 抑制Bok-IP 3R 1相互作用的构建体和肽。获得的结果将提供洞察如何 博克与IP 3R相互作用，并将产生有用的工具，用于探测博克-IP 3R相互作用的意义。 目标二。定义与IP 3R结合的Bok是否调节IP 3R功能。获得的结果应表征 IP 3R调节的新模式，并提供深入了解Bok影响细胞凋亡的机制。 目标3。明确Bok在凋亡信号传导中的作用以及Bok-IP 3R相互作用对该作用的重要性。 所获得的结果将与其他特定目标的数据相结合，以生成一个模型， 影响细胞凋亡，并将确定Bok-IP 3R界面是否是药物靶标。 总之，这一建议是第一次努力，以确定的性质和意义， Bok-IP 3R相互作用，无疑将阐明IP 3R功能和Bok的细胞作用。工作 将促进我们对细胞信号传导和凋亡的理解，并可能确定新的治疗靶点。

Inositol 1,4,5-trisphosphate receptors (IP3Rs) play a pivotal role in vertebrate intracellular signaling. They are a family of three very similar proteins that form tetrameric Ca2+ channels in endoplasmic reticulum (ER) membranes. For the last two decades I have been studying the molecular biology of IP3Rs and recently discovered that Bok, a very poorly understood Bcl-2 protein family member with unique features, binds very strongly to IP3Rs. The Bcl-2 protein family controls the intrinsic apoptosis pathway and is intensively investigated, both from a basic cell biology perspective, and as a target for anti-cancer drugs. Bok is most similar to the well-characterized pro-apoptotic proteins Bax and Bak, but its cellular role remains enigmatic and highly controversial; consensus is, however, that Bok is localized to the ER membrane and plays a role in apoptotic signaling. In the last 3 years, my laboratory has begun to characterize the novel Bok-IP3R interaction and its significance, but there is still much work to do. Now, through three Specific Aims, I plan to test the hypotheses that Bok binding to IP3Rs regulates IP3R function and is required for the role that Bok plays in apoptosis, leaning heavily on newly-developed cell lines in which Bok has been deleted using CRISPR/Cas9- based methods. Aim 1. Resolution of the binding site for Bok on IP3R1 and the development of binding-deficient IP3R1 constructs and peptides that inhibit the Bok-IP3R1 interaction. Results obtained will provide insight into how Bok interacts with IP3Rs and will generate tools useful for probing the significance of the Bok-IP3R interaction. Aim 2. Define whether Bok binding to IP3Rs regulates IP3R function. Results obtained should characterize a new mode of IP3R regulation and provide insight into the mechanism by which Bok influences apoptosis. Aim 3. Define the role of Bok in apoptotic signaling and the importance of the Bok-IP3R interaction to this role. Results obtained will be integrated with the data from the other Specific Aims to generate a model for how Bok influences apoptosis and will establish whether the Bok-IP3R interface is a drug target. In summary, this proposal represents the first effort at characterizing the nature and significance of the Bok-IP3R interaction and will undoubtedly shed light on IP3R function and the cellular role of Bok. The work will both advance our understanding of cell signaling and apoptosis, and may identify a new therapeutic target.