Calcium and Pancreatic Stimulus-Secretion Coupling

钙和胰腺刺激分泌耦合

• 批准号: 7337622
• 负责人: JOHN A WILLIAMS
• 金额: $ 28.54万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7337622
• 关键词: Acetylcholine; Acinar Cell; Actins; Acute; Address; Apical; Area; Assimilations; Calcium; Cell membrane; Cholecystokinin; Complex; Coupling; Cyclic AMP; Cytoplasmic Granules; Cytoskeleton; Disease; Docking; Enzymes; Exocytosis; Family; Food; GTP-Binding Proteins; Gastrointestinal Hormones; Goals; Heterotrimeric GTP-Binding Proteins; Hormones; Inflammatory; Lead; Ligands; Mediating; Membrane; Modeling; Molecular; Monomeric GTP-Binding Proteins; Movement; Myosin ATPase; Neurotransmitters; Numbers; Nutrient; Organ; Pancreas; Pancreatitis; Phosphoric Monoester Hydrolases; Phosphotransferases; Process; Proteins; Proteomics; Public Health; Receptor Activation; Regulation; Research; Role; SNAP receptor; Series; Site; Stimulus; Work; Zymogen Granules; apical membrane; genetic regulatory protein; pancreatic juice; rho; rho GTP-Binding Proteins; trafficking

The overall aim of this research is to understand how regulatory neurotransmitters and gastrointestinal hormones act through changes in intracellular free Ca2+ to bring about digestive enzyme secretion by pancreatic acinar cells. This proposal focuses on the mechanisms involved in the terminal steps in secretion culminating in exocytosis. Using a proteomics discovery strategy, we have identified a number of small GTP binding proteins on the zymogen granule including RabSD, Rab6, Rab11, Rab27B and Rap1. Since Rabs are believed to regulate vesicular trafficking by organizing and regulating effector proteins the focus of this work includes two of these Rab molecules, RabSD and Rab27B as well as Rap1.Two other small G proteins, Rho and Rac which regulate the actin cytoskeleton will also be studied. The overall goal is to determine the role of each of these G proteins in the series of sequential processes by which zymogen granules are brought to the apical membrane, become fusion competent and undergo exocytosis. Specific aims of this proposal include: 1) What is the extent of activation (GTPliganded form) of Rab27B andRap1 on zymogen granules and is it increased by secretagogues such as cholecystokinin (CCK) and acetylcholine? Is Rap1important for secretion as has been shown for RabSD and 27B? Does Rap1 activation mediate the secretory stimulation by cyclic AMP? 2) What are the GEFs or other regulatory protein involved in activating the three granule small G proteins, Rho and Rac? Are they activated by specific heterotrimeric G proteins and/or by intracellular messengers such as Ca2+? Is a cyclic AMP activated GEF (Epac) involved in activating Rap1? 3) What are the downstream effector proteins for RabSD, Rab27B and Rap1? Are linker proteins of the Sip or Slac families involved? Is there a relation of specific small G proteins to myosin Vc? to Noc2? Which small G proteins directly or indirectly regulate SNARE complexes? This work will lead to better molecular understanding of the regulation of digestive enzyme secretion in acinar cells and potential sites for the pathological regulation that occurs in experimental pancreatitis. Relevance to public health: the pancreas is the major organ that secretes digestive breakdown of food and assimilation of nutrients. If these enzymes are not inflammatory disease pancreatitis can result. The present work is directed at understanding of the proteins involved in normal digestive enzyme secretion.

这项研究的总体目的是了解监管神经递质和胃肠道 激素通过细胞内游离Ca2+的变化作用，以通过 胰腺腺泡细胞。该提案重点介绍了分泌终端步骤中涉及的机制 顶点胞吐作用。使用蛋白质组学发现策略，我们已经确定了许多小型GTP 在酶机颗粒上结合蛋白，包括RABSD，RAB6，RAB11，RAB27B和RAP1。自从兔子以来 据信通过组织和调节效应蛋白的重点来调节囊泡贩运 工作包括其中两个Rab分子，RabsD和Rab27b以及Rap1.两个小G 还将研究调节肌动蛋白细胞骨架的蛋白质，RHO和RAC。总体目标是 确定每个G蛋白在Zymogen的一系列顺序过程中的作用 颗粒被带到顶端膜，成为融合能力并患有胞吐作用。具体的 该提案的目的包括：1）rab27b andrap1的激活程度（gtpligand形式）是多少 在酶原颗粒上，胆囊动蛋白（CCK）和 乙酰胆碱？ Rap1immimits的分泌物是否如Rabsd和27b所示？ Rap1 激活通过环状AMP介导分泌刺激？ 2）什么是GEF或其他法规 参与激活三个颗粒小G蛋白Rho和RAC的蛋白质？它们被激活吗 特定的异三聚体G蛋白和/或通过细胞内信使（例如Ca2+）？是循环放大器 激活RAP1激活的GEF（EPAC）？ 3）RABSD的下游效应蛋白是什么， Rab27b和Rap1？ SIP或SLAC家族的接头蛋白是否涉及？是否有特定的关系 肌球蛋白VC的小G蛋白？到Noc2？哪个小的G蛋白直接或间接调节了圈套 复合物？这项工作将导致对消化酶调节的分子理解。 在实验中发生的病理调节的腺泡细胞和潜在位点的分泌 胰腺炎。 与公共卫生有关：胰腺是分泌消化的主要器官 食物分解和营养素的同化。如果这些酶不是 炎性疾病胰腺炎可能导致。目前的工作针对 了解与正常消化酶分泌有关的蛋白质。