Osmolyte Channels in Fish Erthrocytes:Functional and Molecular Properties

鱼红细胞中的渗透通道：功能和分子特性

• 批准号: 0412702
• 负责人: Leon Goldstein
• 金额: --
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0412702&HistoricalAwards=false
• 关键词: Osmolyte; Channels; Fish; Erthrocytes; Functional

Osmolyte Channels in Fish Erythrocytes: Functional and Molecular PropertiesLeon Goldstein Regulation of cell volume is an important physiological mechanism. Cells undergoing physiological dilution of the extracellular fluid and cell division, initially swell, and then, within minutes, restore their normal cell volume. This is accomplished by adjusting their intracellular solute concentrations to match that of the extracellular environment via the transport of osmotically active cell constituents (osmolytes) including ions and organic constituents. During cell swelling, specific protein channels are activated in the cell membrane, which lead to increased release of osmolytes from the swollen cells. Once cell volume is restored the channels are deactivated resulting in cessation of release of osmolytes from the previously swollen cells. Although the functional characteristics of the osmolyte channels have been detailed, their molecular identity is still not clear. Evidence suggests that the cell membrane protein, AE, is involved in the activation of osmolyte transport during cell swelling in fish red blood cells. Recently it has been discovered that there are three genes for the expression of AE proteins in skate (Raja erinacea) red blood cells. This research addresses the questions: Which genes are involved in expression of AE proteins in the red blood cell membranes? Which of the three proteins expressed in the cell membranes function as osmolyte transporters? What are the regulatory factors that activate the transporters during cell swelling? Intact skate red blood cells, isolated red blood cell membranes, and AE protein expression systems in frog eggs will be used to determine: 1. Which of the three AE proteins are expressed in the frog cell. 2. Which of the three AE proteins expressed in the frog egg cell membranes form osmolyte transport channels. 3.Which of the AE proteins in red blood cell membranes localize to lipid domains ('rafts') found on the surface of the cell membranes. 4. Which of several peripheral proteins found in the red blood cell membranes and attached to the AE protein are involved in the regulation of the cell membrane transporters. These studies will provide insights into the molecular and regulatory mechanisms involved in the control of cell volume. Undergraduate and graduate students will be recruited for the project from Brown University , the Mount Desert Island Biological Research Lab and from participation in an existing REU program. In addition, research experiences will be sponsored for high school students recruited from Providence and rural Maine.

鱼类红细胞渗透膜通道的功能和分子特性列昂·戈德斯坦调节细胞体积是一种重要的生理机制。细胞经历细胞外液的生理稀释和细胞分裂，最初会膨胀，然后在几分钟内恢复正常的细胞体积。这是通过调节它们的细胞内溶质浓度以匹配细胞外环境的浓度来实现的，通过运输渗透活性细胞成分(渗透物质)，包括离子和有机成分。在细胞肿胀期间，细胞膜上的特定蛋白通道被激活，导致肿胀细胞释放出更多的渗透调节物质。一旦细胞体积恢复，通道就失活，导致先前肿胀的细胞停止释放渗透物质。尽管渗透膜通道的功能特征已经很详细，但它们的分子特性仍然不清楚。有证据表明，在鱼类红细胞肿胀过程中，细胞膜蛋白AE参与了渗透膜转运的激活。最近发现，溜鱼(Raja Erinacea)红细胞中存在三个表达AE蛋白的基因。这项研究解决的问题是：哪些基因参与了红细胞膜上AE蛋白的表达？细胞膜上表达的三种蛋白质中，哪一种起渗透膜转运蛋白的作用？在细胞肿胀过程中激活转运蛋白的调节因素是什么？将利用完整的冰鞋红细胞、分离的红细胞膜和青蛙卵中的AE蛋白表达系统来确定：1.三种AE蛋白中的哪一种在青蛙细胞中表达。2.在蛙卵细胞膜上表达的三种AE蛋白中，哪一种形成了渗透膜转运通道。3.红细胞膜中的哪种AE蛋白定位于细胞膜表面的脂类结构域(‘筏’)。4.在红细胞膜中发现的与AE蛋白结合的几种外周蛋白中，哪一种参与了细胞膜转运蛋白的调节。这些研究将为控制细胞体积的分子和调控机制提供洞察力。该项目的本科生和研究生将从布朗大学、沙漠山岛生物研究实验室以及参与现有的REU项目中招募。此外，还将为从普罗维登斯和缅因州农村招募的高中生提供研究体验资助。