Polarized Protein Trafficking and Angiogenesis

总结 血管携带氧气和营养物质，对器官活力和持续的体内平衡至关重要。 血管生成，或从已有的血管形成新血管，是主要的发育过程。 调节血管网密度的过程。在血管生成过程中，内皮细胞 形成一个被称为管腔的空腔，为血液到达远处的组织提供一个连续的管道。的 支持内皮结构和信号传导的形态动力学变化的机制， 血管腔的形成或小管发生还不完全清楚。在本提案中，我们将调查一个 一种名为突触结合蛋白样蛋白2（sytl2）的蛋白质，我们认为它负责定义管腔表面 通过在血管发育过程中引导蛋白质运输到顶膜。我们的初步数据 表明sytl2定义了顶膜，并将Rab GT3蛋白系在一起，用于递送囊泡性 货物，如podocalyxin。在目的1中，我们将描述sytl2a在血管腔形成过程中的作用， 使用活体成像和基于CRISPR的突变体生成相结合来开发斑马鱼胚胎。在 在目标2中，我们将全面展示sylt2与GTCLB Rab35结合使用， 足萼蛋白在体外管腔形成过程中对顶端质膜的作用。在目标3中，我们将进一步 表征了sytl2a如何与Rab35相互作用以使用新斑马鱼的一代递送足萼蛋白 报告细胞系和复合突变体。如何调节血管腔的形成仍然是一个主要的 这个建议将为协调这一过程的关键机制提供新的见解。

SUMMARY Blood vessels carry oxygen and nutrients and are vital to organismic viability and continued homeostasis. Angiogenesis, or the formation of new blood vessels from pre-existing ones, is the predominant developmental process by which blood vessel network density is regulated. During angiogenic development, endothelial cells create a hollow cavity called a lumen, providing a continuous conduit for blood to reach distant tissues. The mechanisms underpinning the morphodynamic changes in endothelial architecture and signaling leading to vascular lumen formation, or tubulogenesis, are incompletely understood. In this proposal we will investigate a protein called synaptotagmin-like protein 2 (sytl2) that we believe is responsible for defining the luminal surface by directing protein transport to the apical membrane during blood vessel development. Our preliminary data suggests that sytl2 defines the apical membrane and tethers Rab GTPase proteins for delivery of vesicular cargo, such as podocalyxin. In aim 1, we will characterize the role of sytl2a during vascular lumen formation in developing zebrafish embryos using a combination of live-imaging and CRISPR-based mutant generation. In aim 2, we will comprehensively demonstrate that sylt2 works in combination with the GTPase Rab35 to deliver podocalyxin to the apical plasma membrane during lumenogenesis in vitro. In aim 3, we will further characterized how sytl2a interacts with Rab35 to deliver Podocalyxin using generation of new zebrafish reporter lines and compound mutants in vivo. How blood vessel lumen formation is regulated is still a major question in the field, this proposal will provide novel insight into critical mechanisms orchestrating this process.