SPROUTY, A WT1 TARGET FOR GROWTH AND DEVELOPMENT

描述（由申请人提供）：本申请代表本研究项目的第三次竞争性更新。源于我们对锌指肿瘤抑制蛋白WT1的兴趣，我们发现Sprouty1基因是与肾脏分化和细胞生长调控相关的WT1靶基因。在过去的四年中，我们通过创建Spry1基因敲除小鼠来证实这一想法，该小鼠表现出严重的肾脏表型。我们还发现Sprouty1和其他Sprouty蛋白在ras激活水平上干扰rtk的信号传导。然而，该领域仍存在许多问题，包括其他发芽蛋白在动物发育中的作用；发芽蛋白抑制信号转导的确切作用点和机制以及发芽作用的关键伙伴蛋白。我们认为，这四种萌芽基因在高等真核生物的发育中发挥着不同的作用，并通过一些共同的和一些不同的机制起作用。最后，新出现的数据表明，斯普罗蒂基因可能是真正的肿瘤抑制因子。因此，在下一个资助期，我们提出了一些生化和动物模型方法，以更全面地了解发芽的蛋白质家族。具体来说，我们将。通过敲除细胞和清除野生型和突变型的芽生蛋白，确定芽生蛋白通过Ras/MAP激酶和其他途径在信号转导中的作用点

DESCRIPTION (provided by applicant): This application represents the third competitive renewal for this research program. Orginating from our interesting in the zinc finger tumor suppressor protein WT1, we identified the Sprouty1 gene as a WT1 target gene relevant to kidney differentiation and the regulation of cellular growth. Over the past four years we confirmed this idea through the creation of a Spry1 knockout mouse that exhibited a severe renal phenotype. We also showed that Sprouty1 and other Sprouty proteins interefered with signaling through RTKs at the level of ras activation. Nevertheless many questions remain in the field including the role of the other sprouty proteins in animal development; the exact point of action and mechanism of the sprouty proteins in inhibiting signal transduction and the critical partner proteins for sprouty action. We believe that the four sprouty genes in higher eukaryotes play distinct roles in development and work through some common and some distinct mechanisms. Lastly emerging data suggest that the Sprouty genes may be bonafide tumor suppressors. Hence in the next funding period we propose a number of biochemical as well as animal model approaches towards the fuller understanding of the sprouty family of proteins. Specifically we will 1. Determine the point of action of the sprouty proteins in signal transduction through the Ras/MAP kinase and other pathways through the use of knockout cells and repeletion with wild-type and mutant forms of Sprouty proteins 2. Determine the identity of the critical partner proteins of Sprouty which interact in a phosphorylation dependent and independent manner to modulate signal transduction 3. Determine the role of Sprouty1 as a tumor suppressor protein in an animal model of breast cancer 4. Characterize the biochemical function of the Sprouty 3 protein and target the Spry3 gene in mice to determine the role of this protein in signal transduction and animal development.