Deciphering the molecular mechanisms underlying active scaffolding

 描述（由申请人提供）：细胞外信号调节激酶1和2（ERK 1/2）信号通路在胚胎发育和肿瘤进展的几个关键步骤中发挥重要作用。它还控制关键的细胞功能，如凋亡，运动和分化。这一途径的激酶和磷酸酶已被广泛研究和靶向治疗。然而，决定信号特异性和协调ERK 1/2信号传导的不同生物学结果的机制仍然知之甚少。支架蛋白是ERK 1/2信号通路中的关键参与者，被认为整合传入信号并传递信号特异性，但它们在信号传播中的作用及其作用机制仍然未知。我们研究的长期目标是揭示支架蛋白如何参与ERK 1/2级联调节的生物过程。通过这种方式，可以开发新的治疗策略，以更特异地靶向该级联反应，而不影响其他基本生物功能。 本提案的目的是确定关键支架蛋白Shoc 2调节ERK 1/2介导的细胞运动能力的机制。Shoc 2是胚胎发育所必需的，也是ERK 1/2活性的关键调节因子。我们已经表明，斑马鱼中Shoc 2的缺失导致造血缺陷。我们还发现Shoc 2整合了内吞和泛素机制来调节ERK 1/2信号转导。基于这些初步数据，该提议的中心假设是Shoc 2创建了一个信号中枢，以时空方式调节ERK的发育信号。 我们的假设将通过追求三个具体目标进行测试：目标1将确定Shoc 2支架复合物的时空组织和动力学。目的2揭示E3连接酶HUWE 1调控Shoc 2功能和Shoc 2支架复合物组装的分子机制。目的3将确定通过Shoc 2支架复合物介导的控制胚胎发育的信号传导事件。因此，预计提出的目标将提供对Shoc 2如何参与确定ERK 1/2信号转导结果特异性的详细了解。这些研究将采用最先进的创新显微镜，遗传，分子和细胞技术，并将为我们理解支架蛋白对信号传导的时空控制提供重要见解。这项研究对于促进发育障碍和癌症进展的新型治疗策略和生物标志物创新具有重要意义。因此，拟议的研究与NIH的使命有关，即增加对生物过程的理解，并为疾病诊断、治疗和预防的进展奠定基础。

 DESCRIPTION (provided by applicant): The extracellular signal-regulated kinases 1 and 2 (ERK1/2) signaling pathway plays an essential role in several critical steps of embryonic development and tumor progression. It also controls critical cellular functions such as apoptosis, motility and differentiation. Kinases and phosphatases of this pathway have been extensively studied and targeted therapeutically. However, the mechanisms that determine the signal specificity and orchestrate the diverse biological outcomes of ERK1/2 signaling are still poorly understood. Scaffold proteins are key players in the ERK1/2 signaling pathway that are thought to integrate incoming signals and deliver signaling specificity, and yet their role in signal propagation and the mechanisms of their action are still unknown. The long-term goal of our research is to reveal how scaffold proteins are involved in the biological processes regulated by the ERK1/2 cascade. In this way, new therapeutic strategies can be developed to more specifically target this cascade without affecting other essential biological functions. The objective of this proposal is to determine the mechanisms underlying the ability of the key scaffold protein, Shoc2, to regulate ERK1/2-mediated cell motility. Shoc2 is essential for embryonic development and a critical regulator of ERK1/2 activity. We have shown that depletion of Shoc2 in zebrafish results in defects in hematopoiesis. We also found that Shoc2 integrates endocytic and ubiquitin machineries to regulate ERK1/2 signaling. Based on this preliminary data, the central hypothesis of this proposal is that Shoc2 creates a signaling hub that regulates ERK's developmental signals in a spatio-temporal manner. Our hypothesis will be tested by pursuing three specific aims: Aim 1 will determine the spatio-temporal organization and dynamics of Shoc2 scaffold complexes. Aim 2 will reveal the molecular mechanism by which the E3 ligase HUWE1 controls Shoc2 function and assembly of the Shoc2 scaffold complexes. Aim 3 will determine the signaling events mediated through the Shoc2 scaffold complexes that control embryonic development. The proposed Aims therefore are expected to provide a detailed understanding of how Shoc2 is involved in determining the specificity of ERK1/2 signaling outcomes. These studies will employ state-of-the-art innovative microscopy, genetic, molecular, and cellular techniques and will provide critical insights into our understanding of the spatial-temporal control of signaling by scaffold proteins. This research has significance for contributing to the advancement of novel therapeutic strategies and biomarker innovations for developmental disorders and cancer progression. Thus, the proposed studies are relevant to the NIH's mission to increase understanding of biological processes and to lay the foundation for advances in disease diagnosis, treatment and prevention.