Control of Cell Number in Developing Retina

视网膜发育中细胞数量的控制

• 批准号: 9334004
• 负责人: DUOJIA PAN
• 金额: $ 40.5万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-19 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9334004
• 关键词: Animals; Area; Atrophic; Binding; Biochemical; Candidate Disease Gene; Cell Count; Cell Death; Cell Differentiation process; Cell Nucleus; Cell Proliferation; Cell membrane; Cells; Complex; DNA Binding; Development; Developmental Biology; Drosophila genus; Experimental Models; Eye; Eye Development; Family; Genes; Genetic Screening; Genetic Transcription; Goals; Grant; Growth; Health; Homologous Gene; Hyperplasia; Integral Membrane Protein; Laboratories; Lead; Mammals; Mediating; Modeling; Molecular; Molecular Genetics; Mutation; Names; Neurofibromin 2; Nuclear; Oncogenes; Organ; Organ Size; Organism; Pathway interactions; Phenotype; Phosphotransferases; Physiological; Process; Protein Kinase; Proteins; Regulation; Repression; Research; Retina; Retinal Diseases; Role; Scallop; Signal Pathway; Signal Transduction; Specific qualifier value; System; Therapeutic Intervention; Tissues; Transcription Repressor/Corepressor; Tumor Suppressor Proteins; Verteporfin; apical membrane; base; cancer stem cell; cell type; combinatorial; compound eye; design; extracellular; human disease; in vivo; insight; mutant; novel; programs; small molecule inhibitor; stem cell biology; transcription factor

DESCRIPTION (provided by applicant): My long-term scientific goal is to understand the molecular mechanisms that specify retina cell number. Using the compound eye of Drosophila as an experimental model, my laboratory has discovered the Hippo pathway as a central mechanism underlying this process. The core of the Hippo pathway comprises a kinase cascade in which the Ste20 kinase Hippo (Hpo) phosphorylates and activates the NDR family kinase Warts (Wts). Wts, in turn, phosphorylates and inactivates the oncoprotein Yorkie (Yki) by excluding it from the nucleus, where it normally functions as a coactivator for the DNA-binding transcription factor Scalloped (Sd). Our research further established a critical role for the Hippo pathway in controlling organ size in mammals, underscoring the importance of Drosophila as a powerful model to discover universal developmental mechanisms. Much of our recent efforts have focused on discovering the missing components of the Hippo pathway, with the ultimate goal of defining a complete Hippo signaling network that relays information from the extracellular milieu to nuclear gene transcription. We have made significant progress in the last grant period, including 1) the discovery of Crumbs as an apically localized transmembrane protein that regulates Hippo signaling by directly binding and localizing the tumor suppressor Expanded to apical membranes; 2) discovery of a functionally conserved Hippo pathway in organisms representing unicellular relatives of Metazoa; 3) discovery of verteporfin as the first small molecule inhibitor for Yki and its mammalian homologue YAP; 4) discovery of default repression as a fundamental mechanism underlying Hippo-mediated growth regulation by demonstrating that Sd functions by default as a transcriptional repressor; 5) elucidating the molecular mechanism by which Merlin regulates Hippo signaling by demonstrating a requirement for Merlin in direct binding and recruitment of the effector kinase Wts to the plasma membrane. In the coming project period, we will further elucidate the composition and regulation of the Hippo pathway through the following aims. First, we have identified, through biochemical screens, another protein kinase that can phosphorylate and activate Wts in a similar manner as Hpo. Our goal in this aim is to characterize the role of this Hpo-like kinase in growth control and Hippo signaling in vivo. Second, we have identified, through phenotype-based screens, a novel tumor suppressor that regulates Hippo signaling in a non-cell autonomous manner as well as a tumor suppressor complex that regulates Hippo signaling in a cell-autonomous manner. Our goal in this aim is to understand the molecular mechanisms by which these novel tumor suppressors regulate the Hippo pathway. Lastly, we have designed a sensitized genetic screen to identify additional components of the Hippo pathway. Our goal in this aim is to complete the genetic screen and to molecularly characterize candidate genes identified from the screen. Besides revealing fundamental mechanisms of eye development, the proposed studies will have general implications for the development of other tissues.

描述（由申请人提供）：我的长期科学目标是了解指定视网膜细胞数的分子机制。我的实验室将果蝇的复合眼作为实验模型，发现河马途径是该过程的基础机制。河马途径的核心包括激酶级联反应，其中Ste20激酶河马（HPO）磷酸化并激活NDR家族激酶疣（WTS）。 WT又通过将其从细胞核中排除，从而使肿瘤蛋白约克（YKI）磷酸化并灭活，在该细胞核中通常可以作为DNA结合转录因子扇形（SD）的共激活因子。我们的研究进一步确立了河马的关键作用 控制哺乳动物的器官大小的途径，强调了果蝇作为发现普遍发育机制的强大模型的重要性。我们最近的许多努力都集中在发现河马途径的缺失组件上，其最终目的是定义一个完整的河马信号网络，该网络将信息从细胞外环境转移到核基因转录。我们在最后一个赠款期间取得了重大进展，包括1）将碎屑作为顶端局部跨膜蛋白发现，该蛋白通过直接结合和定位肿瘤抑制剂扩展到顶端膜来调节河马信号传导； 2）在代表Metazoa单细胞亲属的生物体中发现功能保守的河马途径； 3）发现Verteporfin是YKI及其哺乳动物同源物YAP的第一个小分子抑制剂； 4）通过证明SD默认作为转录抑制器的功能来发现默认压抑作为一种基本机制的基本机制； 5）阐明Merlin通过证明梅林在直接结合和募集效应激酶WTS与质膜的直接结合和募集中调节河马信号传导的分子机制。在即将到来的项目期间，我们将进一步阐明通过以下目标的河马途径的组成和调节。首先，我们通过生化筛选确定了另一种蛋白激酶，可以以与HPO相似的方式磷酸化和激活WTS。我们在此目的中的目标是表征这种类似于HPO的激酶在增长控制中的作用 体内河马信号传导。其次，我们通过基于表型的筛查确定了一种新型的肿瘤抑制剂，该肿瘤抑制剂以非细胞自主方式调节河马信号传导以及肿瘤抑制剂复合物，以细胞自动方式调节河马信号传导。我们的目标是了解这些新型肿瘤抑制器调节河马途径的分子机制。最后，我们设计了一个灵敏的遗传筛选，以识别河马途径的其他组件。我们在此目标中的目标是完成遗传筛选，并分子表征从屏幕上鉴定出的候选基因。除了揭示眼睛发育的基本机制外，拟议的研究还将对其他组织的发展具有一般影响。