Signal transduction in development and disease

项目摘要 发育和疾病中的信号转导(PI：Rohatgi) 我的研究项目的目标是发现细胞间通讯的新调节机制 途径，以了解这些机制在疾病状态下是如何受损的，并制定新的策略 来修复它们的功能。在过去的4.5年里，NIGMS的资金支持了全球23种出版物 我的实验室有四个不同的研究领域：HH信号，WNT信号，耐药性 机制和本质上无序的蛋白质。参与Mira支持的研究的受训者获得了 竞争性奖学金(包括NIGMS颁发的K99/R00奖)，并获得独立组长 学术界和工业界的职位。下一个项目期将解决 脊椎动物的HH和WNT信号系统，两个标志性的细胞-细胞沟通途径，协调 组织发育过程中的组织结构及其在成年后的整个生命周期中的维持。尽管 这些通路在从出生缺陷到癌症和退行性疾病等人类疾病中的重要性 在这种情况下，HH和WNT信号的许多步骤在生化和细胞生物学方面仍然知之甚少 水平。在HH途径中，我们的重点是了解信号是如何在细胞表面和 通过质膜传递到细胞质中的转录效应器。这些信令步骤 脊椎动物的HH途径依赖于初级纤毛，即从细胞表面伸出的天线状细胞器。 大多数细胞，并与人类出生缺陷综合征有关，称为“纤毛疾病”。下的主要问题 研究包括：(1)HH配体的受体Patch1(Ptch1)如何调节HH配体的功能 平滑(SMO)，跨膜传递信号的蛋白质，(2)SMO是如何在 初级纤毛和(3)SMO如何向胶质母细胞瘤(GLI)转录因子家族发出信号。我们的米拉- 支持的工作导致了跨膜信号转导的新范式：在 纤毛膜作为第二信使在ptch1和SMO之间传递信号。我们的重点是 在wnt途径中是在多蛋白β-连环蛋白破坏复合体上，该复合体通过 促进β-连环蛋白的降解。这种复合体的缺陷导致了绝大多数的结直肠癌， 负担越来越大的疾病(特别是在50岁以上的人群中)，预计会导致1 到2030年，每年有100万人死亡。我们的重点是发现基因和生化方面的差异 对致癌(突变驱动)和生理(配体驱动)WNT信号的需求，因为 成功的抗WNT药物必须区分这两种药物，才能达到可接受的治疗指数。 我们的工作得到了长期合作的支持，并涵盖了横跨结构的广泛技术 生物学、脂质生物化学、基于CRISPR/CAS9的遗传筛查和显微镜。圆满完成 这个项目将提供对这些基本的小区间通信系统的深入的机械理解 以及监测和调节人类疾病中这些途径的新策略。

Project Summary Signal transduction in development and disease (PI: Rohatgi) The goals of my research program are to uncover new regulatory mechanisms in cell-cell communication pathways, to understand how these mechanisms are damaged in disease states, and to devise new strategies to repair their function. Over the last 4.5 years, funding from the NIGMS has supported 23 publications across four different research areas in my laboratory: Hedgehog (Hh) signaling, WNT signaling, drug resistance mechanisms and intrinsically disordered proteins. Trainees involved in MIRA-supported research have won competitive fellowships (including a K99/R00 award from the NIGMS) and obtained independent group leader positions in both academia and industry. The next project period will tackle major unsolved problems in the vertebrate Hh and WNT signaling systems, two iconic cell-cell communication pathways that coordinate the construction of tissues during development and their subsequent maintenance throughout adult life. Despite the importance of these pathways in human diseases ranging from birth defects to cancer and degenerative conditions, many steps in Hh and WNT signaling remain poorly understood at the biochemical and cell biological level. In the Hh pathway, our focus is on understanding how a signal is detected at the cell surface and transmitted across the plasma membrane to transcriptional effectors in the cytoplasm. These signaling steps in the vertebrate Hh pathway depend on primary cilia, antenna-like organelles that project from the surfaces of most cells and are implicated in human birth defect syndromes called “ciliopathies.” Major questions under investigation include (1) how Patched 1 (PTCH1), the receptor for Hh ligands, regulates the function of Smoothened (SMO), the protein that transmits the signal across the membrane, (2) how SMO is activated at primary cilia and (3) how SMO signals to the Glioblastoma (GLI) family of transcription factors. Our MIRA- supported work has led to a new paradigm in transmembrane signaling: the use of cholesterol accessibility in the ciliary membrane as a second messenger to communicate the signal between PTCH1 and SMO. Our focus in the WNT pathway is on the multi-protein β-catenin destruction complex that suppresses WNT signaling by promoting the degradation of β-catenin. Defects in this complex drive the vast majority of colorectal cancer, a disease with an increasing burden (especially amongst people <50 years of age) predicted to cause over 1 million deaths yearly by 2030. Our emphasis is on uncovering differences in the genetic and biochemical requirements for oncogenic (mutation-driven) and physiological (ligand-driven) WNT signaling, since any successful anti-WNT drug will have to distinguish between the two to achieve an acceptable therapeutic index. Our work is supported by long-term collaborations and embraces a broad range of techniques that span structural biology, lipid biochemistry, CRISPR/Cas9-based genetic screens and microscopy. The successful completion of this project will provide a deep mechanistic understanding of these fundamental cell-cell communication systems and new strategies to monitor and modulate these pathways in human diseases.