REGULATION OF INSP3 RECEPTOR FUNCTION BY MAPK

MAPK 对 INSP3 受体功能的调节

• 批准号: 7137083
• 负责人: BARBARA E. EHRLICH
• 金额: $ 26.21万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7137083
• 关键词: FK506; arachidonate; calcineurin; calcium channel; calcium flux; calcium ion; cell component structure /function; cell nucleus; cytoplasm; electrophysiology; endoplasmic reticulum; enzyme activity; genetic manipulation; genetically modified animals; inositol phosphates; intermolecular interaction; ion transport; laboratory mouse; liver cells; mitogen activated protein kinase; molecular site; nuclear receptors; protein isoforms; protein localization; protein structure function; tissue /cell culture

This project will focus on how growth factors and the activation of the MARK pathway control intracellular Ca2+ in intact cells and will suggest a molecular basis for the specific roles for nuclear and cytosolic Ca2+ signaling and the importance of the regulation of these effects on the growth and function of hepatocytes. Three isoforms of the InsPSR have been identified. The cellular localization of each receptor isoform may be correlated with its functional properties. In hepatocytes the InsPSR type 1 isoform (lnsP3R-1) is cytosolic whereas the type 2 isoform (lnsP3R-2) is found throughout the cell, but is predominantly found in the nucleus and the canalicular region. We hypothesize that in hepatocytes MKP-1 differentially regulates the function and distribution of the InsPSR. In this project the interplay between the InsPSR and MAP kinases will be tested on the activity of single InsPSR channels, the ability of isolated cells to generate transient changes in intracellular Ca2+, and the dynamics of InsPSR distribution. An understanding of these complex interactions is necessary to explain the molecular mechanisms of Ca2+ signaling and thus the regeneraton of liver. The hypotheses to be tested include 1) Does activation of MAPK alter the function of the InsPSR and intracellular Ca2+ signaling? 2) Does MKP-1 inactivation of MAPK alter the function of the InsPSR and intracellular Ca2+ signaling? and 3) Does MAPK phosphorylation modulate the InsPSR isoform distribution within the cell? The preliminary results presented here show for the first time that the InsPSR of hepatocytes are regulated by the MAPK pathway The experiments outlined in this project will investigate the functional of this regulation of the InsPSR at the single channel level and will correlate the channel properties with cell and organ function. The results to be obtained will identify regulatory factors that determine isoform-specific Ca2+ signaling responses, how the cell regulates the channel isoforms to optimize cellular responses, and how this regulation goes awry in pathophysiological situations, such as liver degeneration and regeneration. A long term goal will be to use the molecular information obtained in these studies to suggest useful treatments for individuals affected with liver disease.

该项目将重点介绍生长因素和Mark途径控制细胞内的激活 完整细胞中的Ca2+将为核和胞质Ca2+的特定作用提出分子基础 这些影响对肝细胞生长和功能的调节的信号传导和重要性。 已经确定了INSPSR的三种同工型。每个受体同工型的细胞定位可能是 与其功能特性相关。在肝细胞中，INSPSR 1类同工型（LNSP3R-1）是胞质的 而在整个细胞中都发现了2型同工型（LNSP3R-2），但主要在细胞核中发现 和管道区域。我们假设在肝细胞中MKP-1差异调节功能 和INSPSR的分布。在这个项目中，INSPSR和MAP激酶之间的相互作用将是 测试了单个INSPSR通道的活性，孤立的细胞能够生成瞬态变化 细胞内Ca2+和INSPSR分布的动力学。对这些复杂互动的理解 要解释Ca2+信号传导的分子机制，从而是肝脏的再生所必需的。 要测试的假设包括1）MAPK的激活改变了inspsr和 细胞内Ca2+信号传导？ 2）MAPK的MKP-1失活会改变Inspsr和 细胞内Ca2+信号传导？ 3）dis mapk磷酸化调节INSPSR同工型分布 在牢房内？ 此处介绍的初步结果首次表明肝细胞的INSPSR受到调节 通过MAPK途径，该项目中概述的实验将研究此功能 在单个通道级别调节INSPSR，并将通道性质与单元和细胞和 器官功能。要获得的结果将确定确定同工型特异性的调节因素 Ca2+信号响应，细胞如何调节同工型以优化细胞反应，并且 在病理生理状况（例如肝退化和再生）中，这种调节如何出现问题。 长期目标是使用这些研究中获得的分子信息来提出有用的 针对患有肝病的个体的治疗。