Phosphatidylinositol 4-phosphate Hydrolysis in Spatiotemporal Cell Signaling

时空细胞信号转导中的磷脂酰肌醇 4-磷酸水解

• 批准号: 8756479
• 负责人: Alan V. Smrcka
• 金额: $ 29.17万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8756479
• 关键词: 1,2-diacylglycerol; Address; Affect; Agonist; Apoptosis; Autoimmune Diseases; Binding; Calcium; Cancer Cell Growth; Cardiac; Cardiac Myocytes; Cell Proliferation; Cell membrane; Cell physiology; Cells; Chronic; DNA biosynthesis; Data; Diabetes Mellitus; Diglycerides; Disease; Embryo; Endothelin; Enzymes; Fibroblasts; Functional disorder; G Protein-Coupled Receptor Genes; G-Protein-Coupled Receptors; GTP-Binding Proteins; Goals; Golgi Apparatus; Growth; Heart Diseases; Hormone Receptor; Hydrolysis; In Vitro; Inositol; Laboratories; Link; Malignant Neoplasms; Malignant neoplasm of pancreas; Measures; Membrane; Metabolism; Molecular; Monitor; Mus; Neurotensin; Pancreas; Participant; Pathology; Pathway interactions; Phosphatidic Acid; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phospholipase C; Phospholipids; Phosphoric Monoester Hydrolases; Physiological Processes; Physiology; Play; Prevalence; Process; Production; Protein Isoforms; Protein Kinase C; Protein Tyrosine Kinase; PubMed; Reaction; Receptor Activation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Relative (related person); Role; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Source; Stimulation of Cell Proliferation; System; cell type; in vitro Model; novel; pancreatic cancer cells; phosphatidylinositol 4-phosphate; prevent; public health relevance; receptor; research study; spatiotemporal

DESCRIPTION (provided by applicant): A major cellular signal transduction pathway activated by G protein-coupled receptors and receptor/non- receptor tyrosine kinases is the activation of phosphoinositide-specific phospholipase C (PI-PLC), to stimulate phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis and produce inositol 1,4,5 trisphosphate (IP3) and diacylglycerol (DAG). IP3 controls calcium release from internal stores and DAG regulates protein kinase C. Our laboratory has recently discovered an alternate substrate for PI-PLC activity in cardiac cells, phosphatidylinositol 4-phosphate (PI4P). Hydrolysis of PI4P by PLC produces inositol 1,4 bisphosphate (IP2) which is biologically inert, and DAG. In this application we propose to investigate the broader role for PI4P hydrolysis as source for long-term and localized DAG critical for maintaining compartmentalized and chronically activated protein kinase C and D (PKC and PKD) activities. Protein Kinase C activation is implicated in hundreds of chronic physiological processes. For example, a "PubMed" search of protein kinase C and cancer reveal close to 10,000 references. PKD activation, directly regulated by both PKC, and direct binding of DAG, has recently emerged as a key player in cell physiology and pathology. Thus the experiments outlined in this proposal have the potential to uncover an entirely new fundamental signaling mechanism with potential implications for regulation of a wide range of cell physiologies and pathophysiologies. These issues will be addressed with the following specific aims: 1: Prevalence of the PI4P signaling pathway in cells: We have clearly demonstrated in cardiac myocytes that stimulation of cells with endothelin leads to PI-PLC- dependent depletion of PI4P in the perinuclear Golgi apparatus. The goal of these experiments is to characterize and extend these observations to determine if PI4P hydrolysis plays a prominent role in cell signaling in general. 2: Mechanism for regulation of PI4P hydrolysis. Our preliminary data provide strong evidence for agonist regulated PI4P hydrolysis as a major contributor to long term IP and perhaps DAG production but the signaling pathways and enzymes involved in this process appear to be different depending on the receptor signaling mechanism and cell type. Here we will identify the molecular participants in the signaling pathways that regulate PI4P hydrolysis. 3: Role of PI4P in pancreatic cancer cell signaling, growth, apoptosis and Golgi function: PKC activation is involved in many cellular processes and diseases including cancer. In an established in vitro model of pancreatic cancer, PANC-1 cells, neurotensin potently stimulated PKC and PKD dependent DNA synthesis and cell proliferation and PKD inhibition prevents pancreatic cancer cell growth in vitro. Here we will examine the role of PI4P hydrolysis in activation of key components of this mitogenic signaling pathway and will determine its role in pancreatic cell mitogenesis.

描述（由申请人提供）：由G蛋白偶联受体和受体/非受体酪氨酸激酶激活的主要细胞信号转导途径是磷酸素肌苷特异性磷脂酶C（PI-PLC）的激活，以刺激磷脂酰糖素磷酸4,5-磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸磷酸一点（PIP）1。 （IP3）和二酰基甘油（DAG）。 IP3控制了内部存储中的钙释放，DAG调节了蛋白激酶C。我们的实验室最近发现了一种替代心脏细胞中PI-PLC活性的替代底物， 磷脂酰肌醇4-磷酸（PI4P）。 PLC对PI4P的水解产生肌醇1,4双磷酸（IP2），该双磷酸（IP2）是生物学惰性和DAG的。在此应用中，我们建议研究PI4P水解作为长期和局部dag的来源的更广泛的作用，这对于维持分室化和慢性激活的蛋白激酶C和D（PKC和PKD）活动至关重要。蛋白激酶C激活与数百个慢性生理过程有关。例如，对蛋白激酶C和癌症的“ PubMed”搜索显示近10,000个参考文献。 PKD激活直接由PKC调节，以及DAG的直接结合，最近已成为细胞生理和病理学的关键参与者。因此，该提案中概述的实验有可能发现一种全新的基本信号传导机制，对调节广泛的细胞生理和病理生理学有潜在影响。这些问题将以以下特定目的解决：1：细胞中PI4P信号通路的流行率：我们已经在心肌细胞中清楚地证明，用内皮素刺激细胞会导致PI-PLC依赖于PI4P PI4P在核糖高尔基体中PI4P的耗竭。这些实验的目的是表征和扩展这些观察结果，以确定PI4P水解在一般而言中是否在细胞信号传导中起重要作用。 2：调节PI4P水解的机制。我们的初步数据为激动剂调节的PI4P水解提供了有力的证据，是长期IP以及可能产生DAG的主要贡献者，但根据受体信号机制和细胞类型，参与此过程的信号传导途径和酶似乎是不同的。在这里，我们将确定调节PI4P水解的信号通路中的分子参与者。 3：PI4P在胰腺癌细胞信号传导，生长，凋亡和高尔基体功能中的作用：PKC激活参与包括癌症在内的许多细胞过程和疾病。在建立的胰腺癌体外模型中，PANC-1细胞，神经素蛋白有效刺激PKC和PKD依赖性DNA合成以及细胞增殖以及PKD抑制作用可阻止胰腺癌细胞的体外生长。在这里，我们将研究PI4P水解在这种有丝分裂信号通路的关键成分激活中的作用，并将确定其在胰腺细胞有丝分裂发生中的作用。