The protein phosphatses of arabidopsis thaliana: bioinformatics, biochemistry and function

我的研究项目重点关注一组高度保守的酶（蛋白质），称为蛋白磷酸酶。大多数细胞蛋白质在细胞中以非常特定的方式进行修饰，以响应来自细胞外部或内部的信号来控制其功能。修饰蛋白质的最常见方法是共价连接磷酸基团。这被称为蛋白质磷酸化，添加这种磷酸盐的酶称为蛋白激酶，而去除这种磷酸盐的酶称为蛋白磷酸酶。我的小组使用模式植物拟南芥，通过使用公开的基因组序列数据和其他特征明​​确的生物体（如人类和酵母）的信息，我们在该生物体中鉴定出了一套完整的蛋白磷酸酶。通过检查这些蛋白磷酸酶的氨基酸序列，我们已经能够预测其中几种酶的某些特征，我们现在正在进行生物化学和细胞生物学研究，以进一步定义这些酶的特性和作用。我的团队专注于一型磷酸酶 (PP1)，它通过定义其功能的靶向亚基进行调节。迄今为止，植物中还没有已知的靶向亚基。使用亲和色谱和质谱分析，我们鉴定了 20 种结合蛋白，并建议对其中 3 种进行详细表征，包括假定的核苷激酶 ZAP3。通过生物信息学的见解，我们还将注意力集中在一种全新的叶绿体定位磷酸酶上。这种酶正在被表征，我们相信它可能代表 1 型或 2A 型磷酸酶的古老或祖先形式。通过使用亲和色谱和质谱作为起点，我们还鉴定了一种 2A 型 (PP2A) 复合物，它与其他几种细胞蛋白相互作用，并在控制细胞内蛋白货物的运输中发挥作用。我的研究项目正在基于计算机的观察（生物信息学）与支持这些观察所必需的生物化学、分子和细胞生物学之间架起关键的桥梁。

My research program focuses on a group of highly conserved enzymes (proteins) called protein phosphatases. Most cellular proteins get modified in the cell in very specific ways to allow control of their function in response to signals from outside or within the cell. The most common means of modifying a protein is the covalent attachment of a phosphate group. This is referred to as protein phosphorylation and the enzymes that add this phosphate are called protein kinases and the enzymes that remove this phosphate are protein phosphatases. My group works with the model plant Arabidopsis thaliana and by using the publicly available genome sequence data and information from other well characterized organisms (like humans and yeast) we have identified a complete set of protein phosphatases in this organism. By examining the amino acid sequence of these protein phosphatases we have been able to predict certain features for several of these enzymes and we are now doing the biochemistry and cell biology to further define the properties and role of these enzymes. My group is focusing on the type one phosphatases (PP1), which are regulated by targeting subunits that define their function. As yet, no targeting subunits are known in plants. Using affinity chromatography and mass spectrometry we have identified 20 binding proteins and propose to perform a detailed characterization for 3 of them, including the putative nucleoside kinase ZAP3. Through bioinformatic insights we have also focused our attention on a completely novel chloroplast localized phosphatase. This enzyme is being characterized and we believe it may represent an ancient or ancestral form of the type one or 2A phosphatases. By using affinity chromatography and mass spectrometry as a starting point, we have also identified a type 2A (PP2A) complex that interacts with several other cellular proteins and plays a role in controlling the trafficking of protein cargo in the cell. My research program is making the critical bridge between computer-based observations (bioinformatics) and the biochemistry, molecular and cell biology necessary to support these observations.