Therapeutic effects of cell-permeant peptides that activate G proteins downstream of growth factors
Therapeutic effects of cell-permeant peptides that activate G proteins downstream of growth factors
复制标题
DOI：
10.1073/pnas.1505543112
复制
发表时间：
2015-05-19
影响因子：
11.1
通讯作者：
Ghosh, Pradipta
中科院分区：
文献类型：
--
作者：
Ma, Gary S.;Aznar, Nicolas;Ghosh, Pradipta
在真核生物中，受体酪氨酸激酶（RTK）和三聚体G蛋白是两个主要的信号枢纽。通过三聚体G蛋白的信号转导长期以来一直被认为是由G蛋白偶联受体（GPCR）专门触发的。这种模式最近受到了挑战的多模块信号转导，镓相互作用囊泡相关蛋白（GIV/Girdin）的几项研究。我们最近证明，GIV的C末端（CT）作为一个平台，配体激活的RTK与盖的动态协会，并为非典型的反式激活G蛋白。然而，对这一平台的外源操纵仍然遥不可及。在这里，我们通过将TAT-肽转导结构域（TAT-PTD）融合到GIV的最小模块元件来开发细胞可渗透的GIV-CT肽，所述GIV的最小模块元件对于RTK下游的Gi的激活是必要且足够的，并且使用它们来工程化信号传导网络并改变细胞行为。在完整GEF基序存在的情况下，TAT-GIV-CT肽增强了先前涉及GIV GEF功能的多种过程，例如，刮伤后的2D细胞迁移，癌细胞的侵袭，以及最后，肌成纤维细胞活化和胶原蛋白产生。此外，TAT-GIV-CT肽的局部应用以GEF依赖性方式增强了小鼠中复杂的多受体驱动的伤口修复过程。因此，TAT-GIV肽提供了一种新的和通用的工具来操纵Gai激活下游的生长因子在一系列不同的病理生理条件。
In eukaryotes, receptor tyrosine kinases (RTKs) and trimeric G proteins are two major signaling hubs. Signal transduction via trimeric G proteins has long been believed to be triggered exclusively by G protein-coupled receptors (GPCRs). This paradigm has recently been challenged by several studies on a multimodular signal transducer, Ga-Interacting Vesicle associated protein (GIV/Girdin). We recently demonstrated that GIV's C terminus (CT) serves as a platform for dynamic association of ligand-activated RTKs with Gai, and for noncanonical transactivation of G proteins. However, exogenous manipulation of this platform has remained beyond reach. Here we developed cell-permeable GIV-CT peptides by fusing a TAT-peptide transduction domain (TAT-PTD) to the minimal modular elements of GIV that are necessary and sufficient for activation of Gi downstream of RTKs, and used them to engineer signaling networks and alter cell behavior. In the presence of an intact GEF motif, TAT-GIV-CT peptides enhanced diverse processes in which GIV's GEF function has previously been implicated, e.g., 2D cell migration after scratch-wounding, invasion of cancer cells, and finally, myofibroblast activation and collagen production. Furthermore, topical application of TAT-GIV-CT peptides enhanced the complex, multireceptor-driven process of wound repair in mice in a GEF-dependent manner. Thus, TAT-GIV peptides provide a novel and versatile tool to manipulate Gai activation downstream of growth factors in a diverse array of pathophysiologic conditions.