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

基本信息

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
项目类别：
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

项目摘要

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.

细胞迁移是关键生物学事件中至关重要的过程，例如组织形态发生，免疫响应和癌症转移。多种细胞类型的定向迁移取决于密集的肌动蛋白网络，该网络在细胞前缘迅速形成，并通过肌动蛋白丝的极化伸长来促进其突出。我们已发表的研究揭示了两个新型的互连决定者的肌动蛋白功能在细胞前缘的功能：肌动蛋白的核苷酸编码序列和肌动蛋白精氨酸化。使用结合蛋白质生物化学，细胞生物学和小鼠翻译的综合方法，我的实验室工作表明，精氨酸转移酶（ATE1）（ATE1）是精氨酸蛋白的酶，特异性地调节了细胞迁移过程中肌动蛋白的功能，并且实际上涉及长期群体迁移和组织迁移和组织重新构造的物理学过程。这些研究推动了我的研究计划，该计划旨在通过核乙中编码序列和精氨酸来表征肌动蛋白调节的新机制。我们最近的数据表明，前缘肌动蛋白的N末端精氨酸是一个动态事件，它表现出对细胞外刺激的快速反应，对于维持细胞迁移速度至关重要。此外，精氨酸高度特异性是普遍存在的β-肌动蛋白同工型，但在同一细胞类型中不具有紧密同源的γ-肌动蛋白。值得注意的是，该特异性是通过mRNA编码序列在核苷酸水平上确定的，mRNA编码序列是导致不同肌动蛋白同工型的差异翻译速率，从而对其折叠率和共同翻译泛素化产生了下游影响。这种新型的肌动蛋白调节机制靶向错误的精氨酸肌动蛋白同工型降解，并确保只有快速积累的β-肌动蛋白才能在细胞中精氨酸化。通常以其核丁基序列编码的调节过程，表明精氨酸是在任何其他依赖肌动蛋白依赖性事件之前发生的肌动蛋白调节的主要水平。揭示了这种调节在肌动蛋白功能中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。