Molecular mechanisms of steroid hormone secretion and trafficking

项目总结/摘要 类固醇激素是一个大家族的分子，在儿童发育过程中发挥关键作用。期间 在人类青春期，性腺类固醇激素分泌增加，产生第二性征 例如乳房发育和面部毛发的出现。由于类固醇的重要作用， 激素在成熟过程中，在儿童时期破坏类固醇激素信号可以导致 持续到成年期的发育缺陷了解机构和监管机制， 因此，在正常和病理条件下的类固醇激素信号传导， 促进儿童健康发展。这个项目的最终目标是阐明迄今未知的 类固醇激素释放和运输的机械和调节机制，通过使用果蝇 作为一种模式生物。为了实现这一目的，PI将测试昆虫类固醇 激素蜕皮激素以囊泡介导的方式从类固醇生成组织中分泌， 传统观念认为所有类固醇激素都是通过自由扩散分泌的。在第一个辅导阶段， 项目，PI将与他的导师密切合作，迈克尔奥康纳，在明尼苏达大学， 一些关键的体外方法来阐明他的假设。这些方法包括 蜕皮激素免疫组化检测、体外转运蛋白测定和体外类固醇生成组织培养。 这个初步的建议项目将帮助PI掌握各种生物化学和细胞生物学技术 需要进行项目的下一步。在指导阶段，PI还将接受广泛的 在教学和科学交流方面的培训，这将有助于他的下一个独立阶段。 事业在随后的独立研究者阶段，PI将研究 通过筛选G蛋白偶联受体，推测囊泡介导的蜕皮激素释放， 类固醇生成组织他还将筛选一个假定的蜕皮激素进口所需的外周摄取 组织中这些方法应该告诉我们，这种新的类固醇激素分泌机制， 贩运在不同的生物体中是保守的。从长远来看，PI的工作有可能改变 类固醇激素作用的范例，并将影响对发育和疾病的广泛研究 流程.

Project Summary/Abstract Steroid hormones are a large family of molecules that play pivotal roles during childhood development. During puberty in humans, elevated secretion of gonadal steroid hormones produces secondary sex characteristics such as breast development and the appearance of facial hair. Because of such important roles of steroid hormones in maturation processes, disruption of steroid hormone signaling during childhood can cause developmental defects that last into adulthood. Understanding the machinery and regulatory mechanisms of steroid hormone signaling in normal as well as pathological conditions, therefore, contributes greatly to the promotion of healthy childhood development. The ultimate goal of this project is to elucidate as-yet-unknown machinery and regulatory mechanisms of steroid hormone release and trafficking, by using the fruitfly Drosophila as a model organism. In order to accomplish this purpose, the PI will test the hypothesis that the insect steroid hormone ecdysone is secreted from the steroidogenic tissue in a vesicle-mediated manner, challenging the conventional idea that all steroid hormones are secreted by free diffusion. During the first mentored phase of the project, the PI will work closely with his mentor, Michael O'Connor, at the University of Minnesota to develop some key in vitro methods necessary to elucidate his hypothesis. Those methods include the immunohistochemical detection of ecdysone, in vitro transporter assay and in vitro steroidogenic tissue culture. This initial step of the proposed project will help the PI master various biochemistry and cell biology techniques required to conduct the next step of the project. During the mentored phase, the PI will also undergo extensive training on teaching and scientific communication, which will be helpful in the next independent phase of his career. In the subsequent independent investigator phase, the PI will work on the regulatory mechanisms of the putative vesicle-mediated ecdysone release, by screening G protein-coupled receptors working in the steroidogenic tissue. He will also screen for a putative ecdysone importer required for its uptake by peripheral tissues. These approaches should tell us how well this novel machinery of steroid hormone secretion and trafficking is conserved among different organisms. In the long run, the PI's work has the potential to shift the paradigm of steroid hormone action and will impact a vast range of research on developmental and disease processes.