Deciphering Roles of Cell Shapes in Signaling

 描述(申请人提供)：细胞-细胞信号在发育、内稳态和疾病中起着重要的作用，但在体内调节这种交流的细胞的物理特征令人惊讶地被研究得很少。解剖调节细胞间信号传递的细胞生物学过程将为人类疾病和紊乱的机制提供新的见解，并可能为药物发现提供新的靶点。传统上认为，通过许多途径的远程信号传递涉及配体从信号到接收细胞的扩散，但质膜标记的实时成像表明，隐蔽的细胞延伸有时会远距离连接配体和受体表达细胞，这可能为远程信号转导提供一种不依赖扩散的机制(1-8)。这项拟议的研究利用线虫秀丽线虫作为一个易于处理的系统来破译细胞形状如何调节信号转导，重点是探索细胞延伸在长距离信号转导中的作用。具体目的I将利用基因组工程和复杂的细胞膜和标记蛋白的实时成像来确定体内潜在的信号延伸。特殊目的II将利用基因组工程、遗传操作和共聚焦实时成像来表征一组精心设计的末端细胞延伸的功能，这些延伸可能调节生殖系干细胞的动态。这些实验的结果将通过检测对生殖系干细胞维持、细胞周期和分化的影响来评估。这项工作将为隐蔽细胞形状在发育中的作用提供新的见解，并具有巨大的潜力来扩大我们对细胞-细胞信号机制的了解，并评估扩散信号与接触依赖信号在发育中的作用。

 DESCRIPTION (provided by applicant): Cell-cell signaling plays essential roles in development, homeostasis, and disease, but the physical features of cells that mediate this communication in vivo are surprisingly under-investigated. Dissecting the cell biological processes that regulate intercellular signaling will provide new insights into mechanisms of human diseases and disorders and may suggest new targets for drug discovery. Long-range signaling through many pathways has traditionally been thought to involve diffusion of ligands from signaling to receiving cells, but live imaging of plasma membrane markers has suggested that cryptic cellular extensions sometimes link ligand and receptor expressing cells over long distances, which could provide a diffusion-independent mechanism for long-range signal transduction (1-8). This proposed research utilizes the nematode Caenorhabditis elegans as a tractable system to decipher how cell shapes regulate signal transduction with an emphasis on exploring the roles of cellular extensions in long distance signaling. Specific Aim I will utilize genome engineering and sophisticated live imaging of cell membranes and tagged proteins to identify potential signaling extensions in vivo. Specific Aim II will utilize genome engineering, genetic manipulations, and confocal live imaging to characterize functions for an elaborate set of distal tip cell extensions that may regulate germline stem cell dynamics. The results of these experiments will be assessed by examining effects on germline stem cell maintenance, cell cycles, and differentiation. This work will provide new insights into roles of cryptic cell shapes n development and has great potential to expand our knowledge of cell-cell signaling mechanisms and assess roles of diffusion versus contact-dependent signaling in development.