Regulation and functional characterization of ciliary calcium signaling

睫状体钙信号传导的调节和功能特征

• 批准号: 10245017
• 负责人: Markus G Delling
• 金额: $ 35.53万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10245017
• 关键词: Affect; Amino Acids; Apical; Area; Binding Proteins; Biological; Biological Process; Calcium; Calcium Signaling; Cell Adhesion; Cell membrane; Cells; Cellular biology; Chemicals; Cilia; Cleaved cell; Complex; Congenital Heart Defects; Cyst; Data; Defect; Development; Diffusion; Disease; Electrophysiology (science); Elements; Endoplasmic Reticulum; Endosomes; Environment; Exhibits; Fertilization; G-Protein-Coupled Receptors; Goals; Handedness; Hot Spot; Human; In Vitro; Ion Channel; Ions; Kidney; Kinetics; Knowledge; Learning; Ligands; Light; Lipid Binding; Liver; Mediating; Memory; Methods; Microscopy; Microtubules; Mitochondria; Molecular; Monitor; Mutation; Optics; Organ; Organelles; Output; Pancreas; Permeability; Physiological; Positioning Attribute; Process; Property; Proprotein Convertase 1; Proprotein Convertase 2; Proteins; Regulation; Resolution; SHH gene; Second Messenger Systems; Seminal; Signal Transduction; TRP channel; Testing; Work; base; body system; ciliopathy; congenital heart disorder; human disease; in vivo; mutant; novel; patch clamp; protein transport; tool; trafficking; voltage

PROJECT SUMMARY How can the second messenger Ca2+ regulate a plethora of signaling processes as diverse as fertilization, proliferation, development, learning and memory, contraction and secretion? Compartmentalized Calcium signaling is a fundamental signaling principle by which Ca2+ ions exert their stimulatory function locally in a precisely controlled spatial and temporal manner. Changes in local Ca2+ concentration within the cell are regulated through Ca2+ entry across the plasma membrane to generate “signaling hot spots” or by releasing Ca2+ from intracellular stores such as endoplasmic reticulum (ER), mitochondria or endosomes. Changes in Ca2+ concentration are “sensed” by Ca2+ binding proteins which relay the information into a signaling output. The primary cilium is a microtubule based organelle extending from the apical plasma membrane and shaped like an antenna. Primary cilia are enriched in a specific subset of calcium permeating ion channels called polycystins (PC1 and PC2). While the Ca2+ signaling field has made seminal progress in understanding the molecular principles of compartmentalized Ca2+ signaling in organelles such as ER and endosomes, we are still lacking a functional understanding of the primary cilium as a Ca2+ signaling organelle. Mutations in polycystin ion channels result in a variety of human diseases, ranging from congenital heart disease and laterality defects to cyst formation in multiple organs (liver, kidney and pancreas). Ca2+ is likely to function as a critical second messenger within primary cilia in all of these organs, but the functional consequences of ciliary calcium signaling remain mysterious and so do the mechanisms through which ciliary ion channels are regulated. The central goal of this project is to understand how the cilia ion channels PC1 and PC2 regulate ciliary Ca2+ levels and to determine the cell biological function of compartmentalized ciliary Ca2+ signaling. There are three specific aims. The first aim is to determine how PC1/PC2 channel activity affects ciliary Ca2+ concentration. The second aim tests the hypothesis that changes in ciliary calcium concentration regulate the permeability for proteins of the transition zone, a diffusion barrier at the base of the primary cilium. The third aim determines how the N-terminus of PC1, a 3000 amino acid long fragment decorated with multiple cell adhesion domains, regulates PC1/PC2 ion channel activity. The applicants' preliminary observations include novel unpublished methods to r‐ecord PC1/PC2 channel activity and to dynamically regulate ciliary Ca2+ concentration. Completion of this project will be a critical first step in understanding the cell biological function ciliary calcium signaling. Our long term goal is to understand how dysregulation of ciliary Ca2+ dynamics cause human ciliopathies.

项目摘要 第二使者CA2+如何调节大量的信号传导过程，如受精， 扩散，发展，学习和记忆，收缩和分泌？分隔钙 信号传导是Ca2+离子在A中局部发挥其模拟函数的基本信号原理 精确控制的空间和临时方式。细胞内局部Ca2+浓度的变化是 通过CA2+进入质膜的调节，以生成“信号热点”或发行版 来自内质网（ER），线粒体或内体等细胞内存储的Ca2+。变更 Ca2+结合蛋白将Ca2+浓度“感知”，该蛋白将信息传达到信号输出中。 原发性纤毛是从顶端质膜延伸并形状的基于微管的细胞器 像天线。原发性纤毛富集在钙渗透的离子通道的特定子集中 polycystins（PC1和PC2）。虽然CA2+信号传导字段已使得MAMI-progress了解 诸如ER和内体等细胞器中的分室Ca2+信号传导的分子原理，我们是 仍然缺乏对原代纤毛作为Ca2+信号传导细胞器的功能理解。突变 多囊离子通道导致各种人类疾病，从先天性心脏病和 多个器官（肝，肾脏和胰腺）中的侧向缺陷。 Ca2+可能充当 在所有这些器官中，主要纤毛中的关键第二使者，但纤毛的功能后果 钙信号传导仍然是神秘的，纤毛离子通道的机制也是如此 受监管。该项目的核心目标是了解纤毛离子如何通道PC1和PC2调节 睫状Ca2+水平，并确定分隔纤维Ca2+信号的细胞生物学功能。 有三个特定的目标。第一个目的是确定PC1/PC2通道活动如何影响睫状CA2+ 专注。第二个目的检验了以下假设：睫状钙浓度的变化调节 过渡区的蛋白质的渗透性，过渡区的蛋白，在原发性纤毛的底部的扩散屏障。第三 AIM决定了PC1的N端是如何用多个电池装饰的3000个氨基酸长片段的 粘附域，调节PC1/PC2离子通道活性。申请人的初步观察包括 R -Ecord PC1/PC2通道活动的新型未发表的方法并动态调节睫状CA2+ 专注。该项目的完成将是了解细胞生物学功能的关键第一步 睫状钙信号传导。我们的长期目标是了解睫状CA2+动力学的失调如何导致 人纤毛病。