Mechanism and role of G-protein subunit translocation in cell signaling

G蛋白亚基易位在细胞信号传导中的机制和作用

• 批准号: 8203869
• 负责人: Patrick Ross O'Neill
• 金额: $ 4.84万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8203869
• 关键词: Calcium; Cell membrane; Cell physiology; Cell surface; Cells; Disease; Drug Delivery Systems; Endoplasmic Reticulum; Event; G Beta Gamma; G-Protein-Coupled Receptors; G-substrate; GTP Binding; GTP-Binding Proteins; Golgi Apparatus; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Inositol; Kinetics; Life; Ligand Binding; Mediating; Membrane; Modeling; Molecular; Movement; Pharmaceutical Preparations; Physiological; Process; Property; Protein Family; Protein Subunits; Protein translocation; Proteins; Receptor Activation; Research; Role; Signal Pathway; Signal Transduction; Specific qualifier value; Specificity; Testing; Therapeutic; Therapeutic Agents; design; dimer; evidence base; human disease; new therapeutic target; novel; protein activation; receptor; research study; response; spatiotemporal; therapeutic target; tool

DESCRIPTION (provided by applicant): More therapeutic drugs target G-protein-coupled receptors (GPCRs) than any other family of proteins. G proteins transduce signals initiated at the cell surface through interactions with GPCRs at the plasma membrane (PM). The long term objective of this research is to identify new G protein interactions that can serve as targets for novel therapeutic agents. G protein heterotrimers consist of alpha, beta, and gamma subunits. Upon G protein activation at the PM, the alpha subunit and beta-gamma dimer both activate downstream signaling cascades. Traditionally, both were thought to remain on the PM during this process. Recently, it was discovered that beta-gamma dimers can move off the PM and translocate to the Golgi and endoplasmic reticulum (ER), with targeting and rates that depend on the specific gamma subunit type. These findings call for a better understanding of the mechanisms behind the rapid and reversible movement of G protein subunits in live cells and its function in specifying a cell's response to stimulation of a GPCR. The gamma-dependent kinetics of beta-gamma translocation presents a unique tool for identifying specific G protein-receptor interactions that control translocation, as well as its physiological role. We will exploit these differential kinetics towards two specific aims. Aim 1: Test the hypothesis that interaction between the gamma subunit and the receptor is the primary regulator of receptor-stimulated G-beta-gamma translocation. Aim 2: Test the hypothesis that G-beta-gamma translocation to the endoplasmic reticulum (ER) targets inositol trisphosphate receptors and regulates calcium release. These experiments will test the evidence-based hypothesis that gamma subunits contribute to the specificity of G protein signaling by regulating movement of beta-gamma dimers throughout cell following activation of a GPCR. The findings from the experiments have the potential to identify specific interactions between gamma subunits and receptors that can be targeted to alter the initial events in G protein signaling cascades. Controlling these early events will be important in the treatment of a large number of cell signaling related diseases. PUBLIC HEALTH RELEVANCE: G proteins regulate most of the cell signaling pathways targeted in the treatment of human disease. This research will identify new interactions in G protein signaling that will be important targets for novel therapeutics.