Molecular regulation of the CRAC channel signaling pathway

CRAC通道信号通路的分子调控

• 批准号: 10711690
• 负责人: Xiaowei Hou
• 金额: $ 40.5万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-03 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10711690
• 关键词: Address; Affect; Basic Science; Biochemical; Biochemistry; Calcium; Calcium Channel; Calcium Signaling; Cell membrane; Cell physiology; Cells; Complex; Cryoelectron Microscopy; Disease; Drosophila genus; Endoplasmic Reticulum; Foundations; Genes; Goals; Health; Human; Ion Channel; Knowledge; Lead; Lipids; Mammals; Mediating; Membrane; Methods; Molecular; Pathologic; Pathway interactions; Pharmaceutical Preparations; Physiological; Play; Principal Investigator; Proteins; Regulation; Research; Role; STIM1 gene; Signal Pathway; Signal Transduction; Structure; Tissues; X-Ray Crystallography; cell type; experience; gain of function; gain of function mutation; human disease; innovation; loss of function; loss of function mutation; novel; pharmacologic; programs; protein protein interaction; response; sensor; small molecule; structural biology; therapeutic development; tool

Project Summary/Abstract The calcium (Ca2+) release-activated Ca2+ (CRAC) channels mediate Ca2+ influx in response to Ca2+ store depletion in the endoplasmic reticulum (ER), generating Ca2+ signals critical for many cellular processes. Activation of CRAC channels requires the interaction of Orai and STIM proteins, which are the plasma membrane Ca2+ channel and the Ca2+ sensor in the ER membrane; however, the underlying molecular mechanism remains incompletely understood. Mammals, including humans, have three Orai channels (Orai1, Orai2, and Orai3) and two STIM proteins (STIM1 and STIM2), whereas Drosophila has only one set of Orai and STIM. Both loss- and gain-of-function mutations that underlie human diseases have been identified in human Orai1 and STIM1. The physiological roles of Orai2 and Orai3 are less well understood, but there is emerging evidence showing that they could form heteromeric channels with Orai1, which might play roles distinct from channels formed by Orai1 and STIM1. The long-term goal of my research program is to study the molecular regulation of the CRAC channel signaling pathway in order to understand the molecular mechanisms of the diverse functions the CRAC channels play in different tissues and cells under physiological and pathological conditions. Initially, we are prioritizing structure-function studies of the Drosophila Orai-STIM complex and human CRAC channels to launch my research program. In this proposed research, we aim to address key knowledge gaps in (1) the biochemistry and structural biology of the Orai-STIM interaction, (2) the structure and function of human CRAC channels, and (3) regulation of CRAC channels by cellular factors and channel modulators. We will bring innovative approaches and apply the Principal Investigator’s experience in structural biology and ion channel structure-function studies to address these questions. Specifically, we will determine the atomic structure of the Drosophila Orai-STIM complex as well as structures of human Orai channels and human Orai-STIM complexes. We will also develop novel functional approaches and tools for structure-guided functional analysis of CRAC channels. In addition, we propose to study the regulation of the channel structure and function by small molecule modulators including lipids and pharmacological drugs. Finally, we will use functional, biochemical, and structural biology methods (including both X-ray crystallography and cryo-electron microscopy) to characterize the protein-protein interaction of Orai or STIM with a multitude of endogenous protein regulators. In the next five years, we aim to gain a deeper mechanistic understanding of the regulation of the CRAC channel signaling pathway and construct the foundation of knowledge and research tools to understand and study the broader signaling network in which the CRAC channels reside.

项目摘要/摘要 钙（Ca2+）释放激活的Ca2+（CRAC）通道响应Ca2+存储而介导Ca2+影响 内质网（ER）的耗竭，产生Ca2+信号对许多细胞过程至关重要。 CRAC通道的激活需要ORAI和Stim蛋白的相互作用，这是质膜 Ca2+通道和ER膜中的Ca2+传感器；但是，基本的分子机制仍然存在 包括人类在内的哺乳动物有三个ORAI频道（Orai1，Orai2和Orai3），并且 两种刺激蛋白（STIM1和Stim2），而果蝇只有一组Orai和Stim。损失 - 和 在人Orai1和stim1中已经确定了基础人类疾病的功能性突变。这 Orai2和Orai3的生理作用知之甚少，但是有新的证据表明表明 它们可以与Orai1形成异构频道，这可能扮演与Orai1形成的渠道不同的角色 和stim1。我的研究计划的长期目标是研究CRAC通道的分子调节 信号通路以了解潜水员的分子机制crac通道的功能 在物理和病理条件下在不同的组织和细胞中发挥作用。最初，我们正在优先考虑 果蝇奥莱式复合物和人类CRAC通道的结构功能研究启动我 研究计划。在这项拟议的研究中，我们旨在解决（1）生物化学中的关键知识差距 和Orai stim相互作用的结构生物学，（2）人类CRAC通道的结构和功能，以及 （3）通过细胞因素和通道调节器调节CRAC通道。我们将带来创新的方法 并运用主要研究者在结构生物学和离子通道结构功能研究中的经验 解决这些问题。具体而言，我们将确定果蝇奥莱街的原子结构 人类Orai通道和人类Orai-Stim复合物的复杂以及结构。我们还将发展 新颖的功能方法和工具用于CRAC通道的结构引导功能分析。此外， 我们建议研究小分子调节剂对通道结构和功能的调节 脂质和药物药物。最后，我们将使用功能，生化和结构生物学方法 （包括X射线晶体学和冷冻电子显微镜）以表征蛋白质蛋白 ORAI或刺激与多种内源性蛋白质调节剂的相互作用。在接下来的五年中，我们的目标是 对CRAC通道信号通路的调节和构造有更深入的理解 知识和研究工具的基础，以理解和研究更广泛的信号网络 CRAC通道居住。