Influence of Palmitoylation on GSTP1 Structure, Function, and Cellular Localization.

谷胱甘肽转移酶（GSTs）是一个蛋白质超家族，最著名的是通过催化它们与谷胱甘肽结合来解毒有害的亲电化合物。GSTP1是这个超家族的一个成员。除了在解毒中发挥重要作用外，GSTP1还参与细胞信号传导的调节。像GSTP1这样的蛋白质在细胞中的位置对蛋白质的功能有重要的影响。细胞被组织成悬浮在细胞液中的不同隔间，所有这些隔间都包含在被称为质膜的外层皮肤内。先前的研究认为GSTP1位于细胞液中，但我们发现GSTP1也位于细胞膜中。我们最近发现GSTP1可以被一种叫做棕榈酸酯的脂肪分子修饰。棕榈酸酯修饰可能负责将GSTP1的位置从细胞液移动到细胞膜，并可能具有其他功能。我们正试图精确地确定棕榈酰化在GSTP1上发生的位置，以便我们可以产生一个非棕榈酸修饰的GSTP1突变体。我们正试图了解棕榈酸酯改性对GSTP1结构的影响，我们正在使用多种生化方法来研究这一点。此外，还将研究棕榈酸酯对GSTP1的催化和非催化功能的影响。这将包括研究用棕榈酸酯标记的GSTP1如何与其他蛋白质不同地相互作用。我们还将比较棕榈酸酯修饰的GSTP1与未修饰的GSTP1如何与从细胞系分离的纯脂质和膜相互作用。最后，我们将确定棕榈酸盐标记如何影响GSTP1在细胞中的位置。从这项研究中获得的知识将为GSTP1的基础生物学以及棕榈酸酯修饰如何影响其结构、功能、膜结合和细胞定位提供新的见解。在细胞液中发现的GSTP1形式已被很好地表征，然而，对棕榈酸盐修饰的形式几乎一无所知。该研究将为GSTP1在细胞解毒和信号传导中的多种功能提供新的信息。此外，这些研究结果将对理解棕榈酸酯修饰对其他蛋白质的结构、功能和膜结合的影响具有深远的意义。

Glutathione transferases (GSTs) are a superfamily of proteins best known for detoxifying harmful electrophilic compounds by catalyzing their conjugation with glutathione. GSTP1 is one member of this superfamily. In addition to an important role in detoxification, GSTP1 is involved in the regulation of cell signalling. The location of a protein such as GSTP1 within a cell can have a significant effect on how the protein functions. Cells are organized into different compartments suspended in a cellular fluid, all of which are contained within the outer skin known as the plasma membrane. Studies previously suggested that GSTP1 is located in the cellular fluid, but we have discovered that GSTP1 is also located in cellular membranes. We have recently discovered that GSTP1 can be modified with a fatty molecule called palmitate. Palmitate modification is likely responsible for moving the location of GSTP1 from the cellular fluid to cell membranes and might have additional functions. We are trying to determine precisely where palmitoylation is occurring on GSTP1 so that we can generate a nonpalmitate modified GSTP1 mutant. We are trying to understand the influence the palmitate modification has on the structure of GSTP1 and we are using multiple biochemical approaches to investigate this. In addition, the influence of palmitate on the catalytic and non-catalytic functions of GSTP1 will be investigated. This will include the investigation of how GSTP1 tagged with palmitate interacts differently with other proteins. We will also compare how the palmitate modified GSTP1 interacts with pure lipids and membranes isolated from cell lines versus the nonmodified GSTP1. Lastly, we will determine how palmitate tagging influences where GSTP1 is located in the cell. Knowledge gained from this research will lead to novel insights into the fundamental biology of GSTP1 and how palmitate modification influences its structure, function, membrane association, and cellular localization. The GSTP1 form found in cellular fluid is well characterized, however, virtually nothing is known about the palmitate-modified form. This research will provide novel information for the diverse functions of GSTP1 in cellular detoxification and signalling. In addition, results from these studies will have far reaching implications for understanding the influence of palmitate modification on the structure, function, and membrane association of other proteins.