Regulation of cell migration by nucleotide coding sequence and arginylation

通过核苷酸编码序列和精氨酸化调节细胞迁移

• 批准号: 10552132
• 负责人: Anna S Kashina
• 金额: $ 68.7万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10552132
• 关键词: Actins; Base Sequence; Biological; Cause of Death; Cell Adhesion; Cells; Cellular biology; Code; Data; Defect; Development; Disease; Ensure; Enzymes; Event; Exhibits; Gene Transfer Techniques; Goals; Heart Diseases; Immune response; Lead; Malignant Neoplasms; Messenger RNA; Microfilaments; Morphogenesis; Mus; N-terminal; Neoplasm Metastasis; Nucleotides; Physiological Processes; Process; Protein Biochemistry; Protein Isoforms; Proteins; Publishing; Regulation; Research; Specificity; Speed; Stimulus; Tissues; Translations; Ubiquitination; United States; Work; beta Actin; cell motility; cell type; extracellular; gamma Actin; in vivo; migration; novel; novel therapeutics; programs; response; virtual

Cell migration is a critically important process in key biological events such as tissue morphogenesis, immune response, and cancer metastasis. Directional migration of multiple cell types depends on the dense actin network that rapidly forms at the cell leading edge and facilitates its protrusion via polarized elongation of the actin filaments. Our published studies revealed two novel interconnected determinants of the function of actin at the cell leading edge: actin's nucleotide coding sequence and actin arginylation. Using integrated approaches that combine protein biochemistry, cell biology, and mouse transgenesis, work from my lab demonstrated that arginyltransferase (ATE1), the enzyme that arginylates proteins, specifically regulates the function of actin during cell migration and contributes to virtually every physiologic process involving long-range migration and tissue remodeling in mice. These studies drive my research program, which aims to characterize the novel mechanisms of actin regulation by nucleotide coding sequence and arginylation. Our recent data show that N-terminal arginylation of the leading edge actin is a dynamic event that exhibits a rapid response to extracellular stimuli and is essential for maintaining cell migration speed. Moreover, arginylation is highly specific to the ubiquitous and essential β-actin isoform but not to the closely homologous γ-actin in the same cell types. Remarkably, this specificity is determined at the nucleotide level by the mRNA coding sequence, which is responsible for the differential translation rates of different actin isoforms, exerting downstream effects on their folding rates and co-translational ubiquitination. This novel actin regulatory mechanism targets incorrectly arginylated actin isoforms for degradation and ensures that only the fast­ accumulating β-actin becomes arginylated in cells. Thus, actin arginylation at the cell leading edge is a tightly regulated process that is genetically encoded in its nucleotide sequence, suggesting that arginylation is the primary level of actin regulation that occurs prior to any other actin-dependent event. Uncovering the essential steps of this regulation in actin function and coordination of cell migration in vivo constitutes my long-term research goal.

细胞迁移是组织形态发生、免疫应答和癌症转移等关键生物学事件中至关重要的过程。多种细胞类型的定向迁移依赖于在细胞前缘快速形成的致密肌动蛋白网络，并通过肌动蛋白丝的极化伸长促进其突起。我们已发表的研究揭示了两个新的相互关联的决定因素的肌动蛋白的功能在细胞的前沿：肌动蛋白的核苷酸编码序列和肌动蛋白乙酰化。使用结合联合收割机蛋白质生物化学，细胞生物学和小鼠转基因的综合方法，我实验室的工作表明，乙酰转移酶（ATE 1），一种使蛋白质乙酰化的酶，在细胞迁移过程中特异性调节肌动蛋白的功能，并有助于几乎所有涉及小鼠长距离迁移和组织重塑的生理过程。这些研究推动了我的研究计划，该计划旨在通过核苷酸编码序列和腺苷酸化来表征肌动蛋白调节的新机制。我们最近的数据表明，N-末端乙酰化的前沿肌动蛋白是一个动态的事件，表现出对细胞外刺激的快速反应，是必不可少的维持细胞迁移速度。此外，β-肌动蛋白化对普遍存在的和必需的β-肌动蛋白同种型具有高度特异性，但对相同细胞类型中的密切同源的γ-肌动蛋白没有特异性。值得注意的是，这种特异性在核苷酸水平上由mRNA编码序列决定，该序列负责不同肌动蛋白亚型的差异翻译速率，对它们的折叠速率和共翻译泛素化产生下游效应。这种新的肌动蛋白调节机制靶向不正确的β-肌动蛋白亚型进行降解，并确保只有快速积累β-肌动蛋白在细胞中被β-肌动蛋白化。因此，细胞前沿的肌动蛋白β化是一个严格调控的过程，在其核苷酸序列中遗传编码，表明β化是肌动蛋白调节的主要水平，发生在任何其他肌动蛋白依赖性事件之前。揭示这种调节肌动蛋白功能的基本步骤和体内细胞迁移的协调构成了我的长期研究目标。