Dynamic Protein Palmitoylation in Cell Signaling

细胞信号转导中的动态蛋白质棕榈酰化

• 批准号: 9104881
• 负责人: Askar Akimzhanov
• 金额: $ 32.34万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-16 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9104881
• 关键词: Acyltransferase; Adaptor Signaling Protein; Biochemical; Biological; Biological Assay; Cardiovascular Diseases; Cell membrane; Complex; Cysteine; Disease; Enzymes; Event; Family; Family member; Golgi Apparatus; Homeostasis; Imaging Techniques; Immune System Diseases; Kinetics; Label; Liquid substance; Malignant Neoplasms; Mediating; Membrane Microdomains; Membrane Proteins; Modeling; Molecular; Pathogenesis; Pathway interactions; Physiological; Population; Post-Translational Protein Processing; Protein Dynamics; Protein S; Protein Tyrosine Kinase; Proteins; Receptor Signaling; Recruitment Activity; Regulation; Role; Signal Transduction; Signaling Molecule; Signaling Protein; Stimulus; Substrate Specificity; T Cell Receptor Signaling Pathway; T-Cell Activation; T-Cell Receptor; T-Lymphocyte; Testing; Transferase; base; live cell imaging; member; novel; palmitoylation; protein activation; protein function; public health relevance; research study; response; therapeutic target

 DESCRIPTION (provided by applicant): Although protein S-palmitoylation was discovered more than 30 years ago and palmitoylated proteins have been implicated in pathogenesis of several diseases including cancer, cardiovascular and immune disorders, it remains one of the most understudied post-translational protein modifications. High lability, one of the key features of protein palmitoylation, along with its prominent effect on the protein function makes it an attractive mechanism for the regulation of intracellular signaling. In particular, rapid changes in protein palmitoylation could provide a molecular basis for activation of the plasma membrane-localized signaling proteins by targeting them into specific plasma membrane subdomains. It has been established that activation of the T cell receptor (TCR) signaling pathway is critically dependent on palmitoylation of signaling proteins and their functional association with the liquid ordered plasma membrane subdomains ("lipid rafts") in a palmitoylation-dependent manner. However, molecular mechanisms regulating T cell signaling protein palmitoylation and lipid raft partitioning remain largely unknown. In our preliminary experiments we found that physiologically relevant stimulation of the TCR complex leads to rapid increase in palmitoylation of the tyrosine kinase Lck which is detectable within minutes upon engagement of TCR. To interpret this finding, we propose a model in which the TCR complex recruits and activates plasma membrane associated palmitoyl acyltransferases (PATs) to increase palmitoylation and plasma membrane compartmentalization of T cell signaling proteins. We will investigate this hypothesis in two Specific Aims. In Aim 1 we will determine the role of rapid stimulus-dependent protein palmitoylation in activation of the TCR signaling pathway. We will analyze the dynamics and regulation of stimulus-dependent palmitoylation of Lck, LAT and other members of the TCR signaling pathway. In Aim 2 we will determine if plasma membrane-localized PATs mediate T cell activation. This Aim will potentially uncover a previously uncharacterized role of DHHC PATs in regulation of T cell signaling. Overall, we expect that implementation of a novel class of regulatory enzymes into the canonical TCR signaling pathway would greatly expand a range of potential therapeutic targets for diseases associated with altered T cell homeostasis.

 描述（由适用提供）：尽管在30多年前发现了蛋白质S--甲酰化，并且在包括癌症，心血管和免疫疾病在内的多种疾病的发病机理中已经实施了棕榈酰化的蛋白质，但它仍然是最知名的后经际蛋白质修饰之一。高利益是蛋白质棕榈酰化的关键特征之一，以及其对蛋白质功能的显着影响使其成为调节细胞内信号传导的有吸引力的机制。特别是，快速变化 蛋白质棕榈油化可以通过将其靶向特定的质膜亚域来激活质膜 - 定位信号蛋白。已经确定，T细胞受体（TCR）信号通路的激活至关重要取决于信号蛋白的棕榈酰化及其与棕榈酰化相关方式的功能与液体有序的质膜亚域（“脂质筏”）的功能相关性。然而，分子机制可以预防T细胞信号传导蛋白棕榈酰化和脂质筏分配，这在很大程度上仍然未知。在我们的初步实验中，我们发现对TCR复合物的物理相关刺激导致酪氨酸激酶LCK的棕榈酰化迅速增加，这在TCR参与后几分钟内被检测到。为了解释这一发现，我们提出了一个模型，其中TCR复合物募集并激活质膜相关的棕榈酰酰基转移酶（PATS）以增加T细胞信号传导蛋白的棕榈酰化和质膜隔室化。我们将以两个具体的目的研究这一假设。在AIM 1中，我们将确定快速刺激依赖性蛋白棕榈酰化在TCR信号通路激活中的作用。我们将分析LCK，LAT和其他TCR信号传导途径的刺激依赖性棕榈酰化的动力学和调节。在AIM 2中，我们将确定质膜 - 定位PATS是否介导T细胞激活。该目标可能会发现DHHC PAT在调节T细胞信号传导中的先前未表征的作用。总体而言，我们预计将新型的调节酶实施到规范的TCR信号通路中将大大扩展一系列与T细胞稳态改变有关的疾病的潜在治疗靶标。