Regulation of actin during cell migration

细胞迁移过程中肌动蛋白的调节

• 批准号: 8827384
• 负责人: Anna S Kashina
• 金额: $ 30.4万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8827384
• 关键词: Actins; Address; Amino Acid Sequence; Amino Acids; Binding; Biological; Cause of Death; Cell Adhesion; Cell physiology; Cells; Code; Coupled; Cytoskeleton; Data; Defect; Development; Disease; Embryo; Enzymes; Event; Fibroblasts; Filament; Goals; Health; Heart Diseases; Immune response; Lead; Link; Malignant Neoplasms; Mediating; Messenger RNA; Microfilaments; Morphogenesis; Mus; N-terminal; Neoplasm Metastasis; Phenotype; Physiological; Post-Translational Protein Processing; Property; Protein Isoforms; Proteins; Regulation; Role; Structure; Testing; Tissues; Translations; Ubiquitination; United States; Untranslated RNA; Untranslated Regions; base; beta Actin; cell motility; directional cell; gamma Actin; migration; novel; novel therapeutics; polymerization; prevent; protein degradation; protein structure; research study

DESCRIPTION (provided by applicant): Cell migration drives such key biological events as tissue morphogenesis, immune response, and cancer metastases. Our recent data surprisingly show that the formation and function of the cell leading edge during migration critically depends on arginylation, a relatively unexplored posttranslational modification. Moreover, in cell-based phenotype rescue experiments, we have shown that experimentally arginylated beta actin can largely restore cell leading edge function in mouse embryonic fibroblasts lacking the arginylation enzyme ATE1. In our ongoing studies to determine how N-terminal arginylation of beta actin contributes to lamellipodia formation and directed cell migration, we have made the novel observations that a prominent subset of arginylated beta actin is targeted to the cell leading edge during migration. Moreover, our data demonstrate that beta actin arginylation is selectively regulated by its mRNA sequence rather than its protein structure. In support, gamma actin, which is 99% identical to beta actin at the amino acid level, differs by 13% in its mRNA sequence. We have shown that this difference is directly responsible for faster translation rate of beta actin and leads to its selective arginylation through a novel mechanism coupled to protein ubiquitination. It is also known that zipcode-mediated beta actin mRNA targeting regulates its leading edge localization and, like arginylation, is essential for directional cell migration. We hypothesize that mRNA-mediated regulation of N-terminal arginylation of beta actin uniquely regulates actin function during cell migration by facilitating actin polymerization at the cell leading edge. In this proposal, we will test this hypothesis through three specific aims that will: (1) test the hypothesis that beta actin arginylation facilitates actin polymerization at the cell leading edge; (2) test the hypothesis that beta actin function is uniquely regulated by coding and noncoding regions of its mRNA; and (3) test the hypothesis that this regulation is coupled to modulation of intracellular arginylation activity during cell migration. These experiments will address a novel regulatory mechanism controlling cell polarization and motility through modulating actin's properties and mRNA structure and will ultimately enable a new level of targeted functional studies of cell migration during essential physiological events.

描述（由申请人提供）：细胞迁移驱动组织形态发生，免疫反应和癌症转移等关键生物学事件。我们最近的数据令人惊讶地表明，迁移过程中细胞前缘的形成和功能取决于精氨酸，这是一种相对未开发的翻译后修饰。此外，在基于细胞的表型救援实验中，我们已经表明，实验精氨酸β肌动蛋白在很大程度上可以在缺乏精氨酸酶ATE1的小鼠胚胎成纤维细胞中恢复细胞前缘功能。在我们正在进行的研究中，以确定β肌动蛋白的N末端精氨酸如何有助于层状脂蛋白膜片和定向细胞迁移，我们已经表达了新的观察结果，即在迁移过程中，精氨酸化β肌动蛋白的显着子集针对细胞领先。此外，我们的数据表明，β肌动蛋白精氨酸由其mRNA序列而不是其蛋白质结构选择性调节。为了支持，γ肌动蛋白在氨基酸水平上与β肌动蛋白相同的99％在其mRNA序列上差异13％。我们已经表明，这种差异直接导致更快的翻译速率 β肌动蛋白并通过与蛋白质泛素化结合的新机制导致其选择性精氨酸化。众所周知，邮政编码介导的β肌动蛋白mRNA靶向的靶向前缘定位，并且像精氨酸一样，对于定向细胞迁移至关重要。我们假设mRNA介导的β肌动蛋白N末端精氨酸的调节通过促进细胞前缘的肌动蛋白聚合在细胞迁移过程中独特地调节肌动蛋白功能。在此提案中，我们将通过三个特定目标来检验这一假设： （1）检验β肌动蛋白精氨酸促进肌动蛋白聚合在细胞前缘的假设； （2）检验以下假设：β肌动蛋白功能受其mRNA的编码和非编码区域的唯一调节； （3）检验以下假设：该调节与细胞迁移过程中细胞内精氨酸活性的调节耦合。这些实验将通过调节肌动蛋白的特性和mRNA结构来解决一种控制细胞极化和运动性的新型调节机制，并最终将在基本生理事件期间对细胞迁移的新靶向功能研究进行新的水平。