REDOX EFFECTS ON THE STRUCTURE AND DYNAMICS OF PRL-1

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 拟议的研究的长期目标是表征蛋白酪氨酸磷酸酶（PTH 4）PRL-1的固有构象动力学如何通过修饰来稳定，以及修饰如何影响磷酸酶活性和细胞功能。PRL最初被鉴定为促进部分肝切除后大鼠肝再生的早期反应基因。最近，发现这些酶的过度表达会引发转移并促进肿瘤形成。在每种情况下都需要磷酸酶活性，但蛋白质定位于独特的细胞位置，因此识别指导差异细胞定位和结果的生化开关至关重要。信号传导是通过结构变化驱动的瞬时特异性相互作用完成的，这些结构变化通常受到化学修饰的影响。这些修饰充当分子功能的开关，控制重要的生物过程。PRL-1在调节细胞生长相关信号中的具体作用尚未确定，也不知道PRL-1本身是如何调节的。将使用标准的杂原子溶液NMR方法来分配化学位移共振，并获得结构计算的限制。弛豫分析将被用来表征蛋白质中的骨架酰胺的动态运动，并提供有关开放和封闭状态之间的相互转换所涉及的构象变化的信息，这是由活性位点Cys的氧化还原状态调节。Tyr磷酸化对PRL-1结构和活性的影响也将在这两种状态下进行研究。了解PRL-1活性如何通过二硫键形成和翻译后修饰来调节，将为确定药物设计的目标PRL-1构象提供关键细节。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term objective of the proposed research is to characterize how inherent conformational dynamics of the protein tyrosine phosphatase (PTPase) PRL-1 are stabilized by modification and how modification influences phosphatase activity and cellular function. PRLs were originally identified as early response genes that promote liver regeneration in rats after partial hepatectomy. More recently, over-expression of these enzymes was found to trigger metastasis and promote tumor formation. In each case phosphatase activity is required, but the protein is localized to a unique cellular location, making it critical to identify biochemical switches that direct differential cellular localization and outcomes. Signaling is accomplished through transient, specific interactions driven by changes in structure, which are often influenced by chemical modification. These modifications act as switches in molecular function, controlling important biological processes. The specific role of PRL-1 in regulating signals related to cell growth has not been determined, nor is it known how PRL-1 itself is regulated. Standard heteronuclear solution NMR methods will be used to assign chemical shift resonances and obtain restraints for structure calculations. Relaxation analysis will be used to characterize the dynamic motion of backbone amides in the protein and provide information about conformational changes involved in interconversion between the open and closed states, which are regulated by the redox state of the active site Cys. The affect of Tyr phosphorylation on PRL-1 structure and activity will also be examined with respect to the two states. Understanding how PRL-1 activity is regulated by disulfide formation and post-translational modification will provide critical details to identify which conformation of PRL-1 to target for drug design.