Phosphoinositide Signaling in the Cytosol and Nucleus

细胞质和细胞核中的磷酸肌醇信号转导

• 批准号: 10561701
• 负责人: Richard A. Anderson
• 金额: $ 70.71万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10561701
• 关键词: Agonist; Binding; Biological Process; Cardiovascular Diseases; Cell Nucleus; Cell Proliferation; Cell Survival; Cell membrane; Cell physiology; Cytosol; DNA Repair; Diabetes Mellitus; Diagnostic; Disease; EGF gene; Endosomes; Epidermal Growth Factor Receptor; Event; Gene Expression; Generations; Genes; Immune System Diseases; Link; MAP4; Malignant Neoplasms; Membrane; Microtubules; Neurodevelopmental Disorder; Neurons; Nuclear; Outcome; PDPK1 gene; PIK3CG gene; PTEN gene; Pathway interactions; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phosphotransferases; Polymerase; Process; Protein Dephosphorylation; Regulation; Research; Resistance; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Stress; System; TP53 gene; Therapeutic; Tumor Suppressor Proteins; biological adaptation to stress; cancer cell; inorganic phosphate; inositol polyphosphate multikinase; novel; receptor; scaffold; Agonist; Binding; Biological Process; Cardiovascular Diseases; Cell Nucleus; Cell Proliferation; Cell Survival; Cell membrane; Cell physiology; Cytosol; DNA Repair; Diabetes Mellitus; Diagnostic; Disease; EGF gene; Endosomes; Epidermal Growth Factor Receptor; Event; Gene Expression; Generations; Genes; Immune System Diseases; Link; MAP4; Malignant Neoplasms; Membrane; Microtubules; Neurodevelopmental Disorder; Neurons; Nuclear; Outcome; PDPK1 gene; PIK3CG gene; PTEN gene; Pathway interactions; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phosphotransferases; Polymerase; Process; Protein Dephosphorylation; Regulation; Research; Resistance; Role; Second Messenger Systems; Signal Pathway; Signal Transduction; Stress; System; TP53 gene; Therapeutic; Tumor Suppressor Proteins; biological adaptation to stress; cancer cell; inorganic phosphate; inositol polyphosphate multikinase; novel; receptor; scaffold

PROJECT SUMMARY. This research seeks to understand spatial phosphoinositide signaling (PI) mechanisms in the cytosol and nucleus. These pathways have broad implications for cancer, neurodevelopmental disorders, diabetes, and several congenital diseases. In the cytosol, agonists, such as EGF (and many others), activate signaling pathways that control most cellular functions. In the nucleus, these pathways are separate from known membrane compartments but control stress responses that impact DNA repair, cell survival, and other events. Agonists activated PI3K signaling occurs through the IQGAP1 scaffold that assembles multiple pathways including the PI 3-kinase and Erk pathways. Yet, how the IQGAPs assemble specific signaling pathways is not understood. We will focus on the assembly of the full PI 3-kinase pathway on IQGAPs. This includes the assembly of the PI 4-kinase (PI4KIII), type I PIP 5-kinase (PIPKI), PI3K, Ras, PDK1 and Akt into the scaffold. Remarkably, we show that IQGAP2 and IQGAP3 also assemble the PI 3-kinase pathway components but with different outcomes. IQGAP2 is tumor suppressor in cancer cells whereas IQGAP1 and IQGAP3 promote PI3K signaling and cell proliferation. Here, we will explore how receptors stimulate the assembly of the IQGAPs signaling pathways with an emphasis on the EGF receptor and IQGAP1-PI 3-kinase and Erk pathways. We will emphasize spatial PI 3-kinase signaling at endosomal compartments at proximity to microtubules by linkage with microtubule associated protein 4 (MAP4) that interacts with IQGAP1 and PI 3-kinase. The link between the cytosolic and nuclear PI signaling is the PIPKI, which generates PIP2 in the cytosol and nucleus Nuclear PI signaling remarkably is not associated with membrane compartments. We showed that a nuclear poly(A) polymerase, Star-PAP (for speckle targeted PIPKI regulated-poly(A) polymerase), associates with PIPKI and is activated by phosphatidylinositol-4,5-bisphosphate (PIP2). Star-PAP controls ~40% of genes and is regulated by many signals. Recently, we have shown that PIPKI also binds to the tumor suppressor p53, and that p53 is a PIP2 effector. The binding of PIP2 stimulates p53’s interactions with other nuclear factors that control p53 function. Both Star-PAP and p53 are also regulated by inositol polyphosphate multikinase (IPMK) that generates phosphatidylinositol-3,4,5-trisphosphate (PIP3) associated with p53, and nuclear PTEN that dephosphorylates this PIP3. We have identified Star-PAP and p53 as two key effectors of nuclear phosphoinositide signaling during stress signaling. This proposal will focus on the mechanism and impact of this stress pathway on Star-PAP functions. Remarkably the PIPn is so tightly associated with Star-PAP and p53 that it is stable to SDS-PAGE suggesting a covalent linkage and we will explore how PIP2 is linked to Star-PAP and p53. Is this covalent or a very tight interaction that is resistant to denaturation? Our findings indicate new avenues for potential therapeutic control of both the cytosolic and nuclear PI pathways as these pathways have fundamental implications in many disease processes but with an emphasis on cancer.

项目摘要。该研究试图了解空间磷酸肌醇信号传导（PI）机制 在细胞质和核中。这些途径对癌症，神经发育障碍具有广泛的影响， 糖尿病和几种先天性疾病。在细胞质中，激动剂，例如EGF（以及许多其他），激活 控制大多数细胞函数的信号通路。在细胞核中，这些途径与已知的途径分开 膜室但控制着影响DNA修复，细胞存活和其他事件的应力反应。 激动剂激活的PI3K信号传导通过IQGAP1支架发生，该脚手架组装了多个途径 包括PI 3-激酶和ERK途径。但是，IQGAP如何组装特定的信号通路不是 理解。我们将专注于IQGAP上完整的PI 3-激酶途径的组装。这包括 PI 4-激酶（PI4KIII）的组装，IPIP5-激酶（PIPKI），PI3K，RAS，PDK1和AKT的组装 脚手架。值得注意的是，我们表明IQGAP2和IQGAP3还组装了PI 3-激酶途径组件 但是有不同的结果。 IQGAP2是癌细胞中的肿瘤抑制剂，而IQGAP1和IQGAP3促进 PI3K信号传导和细胞增殖。在这里，我们将探讨接收器如何刺激IQGAP的组装 信号通路，重点是EGF受体和IQGAP1-PI 3-激酶和ERK途径。我们将 强调通过与微管接近微管的内体隔室处的空间PI 3-激酶信号传导 与IQGAP1和PI 3-激酶相互作用的微管相关蛋白4（MAP4）。在 胞质和核PI信号是PIPKI，它在细胞质和核中产生PIP2 核PI信号传导显着与膜室无关。我们证明了核 聚（A）聚合酶，Star-PAP（用于斑点靶向PIPKI调节 - 聚合酶（A）聚合酶），与 pipki并被磷脂酰肌醇-4,5-双磷酸盐（PIP2）激活。星-PAP控制〜40％的基因和 受许多信号监管。最近，我们表明PIPKI也与肿瘤抑制剂p53结合， p53是PIP2效应器。 PIP2的结合刺激了p53与其他核因素的相互作用 控制p53功能。星-PAP和p53也受肌醇多磷酸多次次次酶（IPMK）调节 这会产生磷脂酰肌醇-3,4,5-三磷酸（PIP3）与p53相关的，以及核PTEN 去磷酸化该PIP3。我们已经将Star-PAP和p53确定为核的两个关键影响 应力信号传导期间的磷酸肌醇信号传导。该提议将重点放在此的机制和影响上 星-PAP功能上的应力途径。值得注意的是，PIPN与Star-Pap和P53紧密相关，以至于 它与SDS-PAGE稳定，暗示了共价链接，我们将探讨PIP2如何链接到Star-PAP和 p53。这种共价还是非常紧密的相互作用？我们的发现表明了新的途径 对于胞质和核PI途径的潜在理论控制，这些途径具有 在许多疾病过程中的基本意义，但重点是癌症。