Functional Analysis of the Bifunctional Ion Channel and Kinase TRPM7

双功能离子通道和激酶 TRPM7 的功能分析

基本信息

批准号：
8439467
负责人：
LOREN W RUNNELS
金额：
$ 18.18万
依托单位：
UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-05-01 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8439467
关键词：
Adult Affect Biochemical Biological Brain Ischemia Cations Cell Proliferation Cells Congenital Abnormality Defect Development Developmental Gene Embryo Embryonic Development Figs - dietary Funding Homeostasis Homologous Gene Human Incubated Individual Intake Ion Channel Lead Life Magnesium Malignant Neoplasms Mediating Medical Molecular Biology Movement Mus Neural Fold Neural Tube Closure Neural Tube Defects Neural tube Pathway interactions Phosphotransferases Play Pregnancy Prevention strategy Process Proteins Regulation Reporting Research Risk Role Signal Transduction Spinal Dysraphism Staging Stroke Supplementation System Time Tissues United States Xenopus Xenopus laevis Yeasts cancer cell cell behavior cell motility combat cost gain of function gastrulation human disease in vivo innovation insight loss of function mRNA Expression neuron loss novel offspring prevent protein expression protein function public health relevance research study tissue/cell culture xenopus development yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): Neural fold closure defect (NTD) is one of the most common birth defects in humans, occurring at an average rate of 1 per 1000 pregnancies. Decreased maternal Mg2+ intake has been associated with an increased risk for NTD, suggesting a key role for Mg2+-permeant ion channels in this essential stage of development. Our research in Xenopus laevis has uncovered important roles for the TRPM6 and TRPM7 ion channels in gastrulation and neural fold closure during embryogenesis. Neural fold closure defects caused by depletion of TRPM7 from Xenopus laevis embryos can be prevented by Mg2+ supplementation or by expression of a Mg2+ transporter, supporting the hypothesis that Mg2+ and the ion channels that conduct this important cation play a critical role during this essential embryonic process. TRPM7 and TRPM6 are known to hetero-oligomerize when heterologously expressed in tissue culture cells, but reports vary as to whether TRPM6 functions by itself as a channel in vivo. Preliminary studies indicate that TRPM6 mRNA expression is upregulated during gastrulation and peaks during neurulation, supporting the hypothesis that the two channels are functioning together to regulate neural fold closure. We propose three specific aims to clarify the function and regulation of these two channels during early development. In the first specific aim, we will employ loss-of-function and gain-of-function experiments in Xenopus laevis to define the role of TRPM6 during development and its connection to the non-canonical Wnt pathway, which has been shown to regulate convergent extension movements during gastrulation and neural fold closure. In specific aim 2 we will examine in Xenopus how TRPM6 and TRPM7 and its individual domains may be functioning together to regulate neural fold closure and how these channels may be impacting Mg2+ homeostasis in the developing embryo. Our research will also focus on how TRPM7's control of Mg2+ homeostasis is affecting the migratory behavior of cells. In specific aim 3 we will investigate the role of 80K-H, a TRPM6- and TRPM7-interacting protein that functions synergistically with TRPM7 during gastrulation and neural fold closure, has in regulating these channels' protein levels, and determine how the Wnt pathway may be impacting this regulation. Collectively, the proposed experiments should greatly advance our understanding how these unique bifunctional channels are functioning in vivo, which could lead to new strategies for preventing neural tube closure defects as well as to new insights for combating the other pathological conditions for which these channels have been associated, including stroke and cancer.

描述（由申请人提供）：神经折叠闭合缺陷（NTD）是人类最常见的先天缺陷之一，以每1000次怀孕的平均率为1。孕产妇MG2+摄入量的减少与NTD的风险增加有关，这表明在这一发展的基本阶段，MG2+ permemant离子通道的关键作用。我们在Xenopus laevis中的研究发现了胚胎发生过程中TRPM6和TRPM7离子通道的重要作用。通过MG2+补充或表达MG2+转运蛋白的表达，可以预防由TRPM7耗尽引起的神经折叠闭合缺陷，这支持MG2+和ION通道在这一基本胚胎过程中在这一重要的胚胎过程中起着至关重要的作用。众所周知，当在组织培养细胞中异源表达时，trpm7和trpm6是杂产的，但是报告TRPM6是否自身起作用是体内通道。初步研究表明，在胃结构和神经期间的峰值期间，TRPM6 mRNA表达在上调，这支持了这两个通道一起起作用以调节神经折叠闭合的假设。我们提出了三个特定的目标，以阐明早期开发期间这两个渠道的功能和调节。在第一个特定目标中，我们将在Xenopus laevis中采用功能丧失和功能获得实验来定义TRPM6在开发过程中的作用及其与非统治WNT途径的联系，该途径已显示出在胃折线和神经折叠过程中调节收敛的扩展运动。在特定目标2中，我们将在Xenopus中检查TRPM6和TRPM7及其各个域如何共同起作用以调节神经折叠的闭合以及这些通道如何影响发育中的胚胎中的MG2+稳态。我们的研究还将集中于TRPM7对MG2+稳态的控制如何影响细胞的迁移行为。在特定目标3中，我们将研究80K-H，TRPM6和TRPM7相互作用蛋白的作用，该蛋白在胃肠道和神经折叠过程中与TRPM7协同起作用，在调节这些通道的蛋白质水平方面具有与TRPM7的作用，并确定WNT途径如何影响该法规。总的来说，拟议的实验应极大地促进我们了解这些独特的双功能通道如何在体内发挥作用，这可能会导致防止神经管闭合缺陷的新策略，以及与这些通道相关的其他病原体条件（包括中风和癌症）相关的其他病理条件的新见解。