Acinar Cell Biology and Pancreatic Disease

腺泡细胞生物学和胰腺疾病

• 批准号: 7367045
• 负责人: GUY E GROBLEWSKI
• 金额: $ 28.05万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-08 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7367045
• 关键词: Acinar Cell; Acinus organ component; Address; Annexin A6; Antibodies; Apical; Area; Binding; Binding Proteins; Biochemical; Calcium; Cell membrane; Cell physiology; Cell secretion; Cells; Cellular Morphology; Cellular biology; Clathrin; Complex; Condition; Cytoplasm; Development; Dissociation; Dominant-Negative Mutation; Early Endosome; Elevation; Endocytosis; Endosomes; Enzyme Precursors; Enzymes; Epithelial Cells; Event; Exocytosis; Fluids and Secretions; Fractionation; Future; Golgi Apparatus; Heating; Immunoblotting; Immunoelectron Microscopy; In Vitro; Infection; Integral Membrane Protein; Liquid substance; Lysosomes; Maps; Mediating; Membrane; Membrane Fusion; Membrane Protein Traffic; Membrane Proteins; Microfilaments; Molecular; Mutation; Nature; Neurons; Orthologous Gene; Pancreas; Pancreatic Diseases; Pancreatic duct; Pancreatitis; Pathway interactions; Peptides; Personal Satisfaction; Phase; Phospholipids; Phosphorylation; Physiological; Play; Process; Proteins; Rattus; Recycling; Regulation; Reporting; Research Design; Research Personnel; Role; SNAP receptor; Series; Serine; Serine Phosphorylation Site; Site; Sorting - Cell Movement; Staging; Structure; TPD52L1 gene; Techniques; Testing; Therapeutic; Time; Trypsinogen; Vesicle; Work; Zymogen Granules; apical membrane; calcium-regulated heat-stable protein 28; concept; drug discovery; genetic regulatory protein; insight; mutant; novel; research study; response; sensor; theories; trafficking

The pivotal role of Ca2+ in regulating pancreatic acinar cell function under normal and pathophysiological conditions is well established, however, the molecular changes that occur in response to elevated Ca2+ are largely unknown. This proposal addresses a novel mechanism by which cytosolic Ca2+ modulates the trafficking of phospholipids and associated regulatory proteins in the secretory and endocytic pathways in acinar cells. Calcium responsive heat-stable protein (CRHSP-28) is a key regulatory molecule in the secretory pathway of acinar cells. CRHSP-28 is highly modulated by changes in cellular Ca2+ as indicated by its Ca2+-dependent 1) regulation of digestive enzyme secretion, 2) interaction with the vesicletrafficking protein annexin VI, and 3) serine phosphorylation, which triggers the release of CRHSP-28 from a membrane associated complex. The primary objective of this proposal is to test the hypothesis that CRHSP- 28 acts as Ca2+-sensor to promote and stabilize key protein interactions necessary for acinar cell membrane trafficking. In Specific Aim 1 experiments will address the concept that interaction of CRHSP-28 with annexin VI directs CRHSP-28 association with endosomes that are necessary to support secretory function. Site specific mutants targeting the annexin VI binding domain will be expressed in acini and effects on zymogen secretion and membrane trafficking determined. Specific Aim 2 will utilize CRHSP-28 mutants that alter the major CRHSP-28 phosphorylation site, serine 136, to test the theory that phosphorylation inhibits CRHSP-28 function by displacing it from a membrane-bound state. Specific Aim 3 will address the hypothesis that CRHSP-28 regulates an apical membrane trafficking pathway that is distinct from zymogen granules and acts to shuttle important regulatory molecules to the apical membrane. Elucidation of the molecular mechanism by which CRHSP-28 modulates exocrine function should provide valuable insight into the.Ca2+- dependent nature of the secretory pathway in acinar cells, which is essential for the development of therapeutic strategies aimed at the treatment of exocrine pancreatic disease. This proposal is aimed at understanding the biochemical mechanism by which changes in cell Ca2+ regulate pancreatic function in normal and pathological states. As such, these studies will help to identify potential targets for drug discovery and therapeutic strategies ajmed at treating pancreatic disease.

正常和病理生理条件下Ca~（2+）对胰腺腺泡细胞功能的调节作用 条件已经建立，然而，响应于升高的Ca2+而发生的分子变化是 大部分未知。这一建议提出了一种新的机制，细胞内Ca 2+通过这种机制调节细胞内Ca 2+的水平。 磷脂和相关调节蛋白在分泌和内吞途径中的运输 腺泡细胞钙应答热稳定蛋白（CRHSP-28）是钙离子通道的关键调节分子， 腺泡细胞的分泌途径。CRHSP-28受细胞Ca2+变化的高度调节，如所示 通过其Ca 2+依赖性1）调节消化酶分泌，2）与囊泡运输相互作用 蛋白膜联蛋白VI，和3）丝氨酸磷酸化，其触发CRHSP-28从膜上释放。 膜缔合复合物本提案的主要目的是检验CRHSP- 28作为Ca2+传感器促进和稳定腺泡细胞膜所必需的关键蛋白质相互作用 贩卖人口在具体目标1中，实验将阐述CRHSP-28与膜联蛋白的相互作用 VI指导CRHSP-28与支持分泌功能所必需的内体缔合。网站 靶向膜联蛋白VI结合结构域的特异性突变体将在腺泡中表达， 分泌和膜运输确定。特异性目标2将利用CRHSP-28突变体， CRHSP-28的主要磷酸化位点丝氨酸136，以检验磷酸化抑制CRHSP-28的理论 通过将其从膜结合状态转移而发挥作用。具体目标3将解决以下假设： CRHSP-28调节与酶原颗粒不同的顶膜运输途径， 用于将重要的调节分子穿梭至顶膜。分子解析 CRHSP-28调节外分泌功能的机制应提供有价值的见解。 腺泡细胞中分泌途径的依赖性，这对于 旨在治疗胰腺外分泌疾病的治疗策略。 该建议旨在了解细胞中Ca2+调节的生化机制 胰腺功能正常和病理状态。因此，这些研究将有助于确定潜在的 用于治疗胰腺疾病的药物发现和治疗策略的靶点。