REGULATION AND FUNCTION OF UROPLAKIN GENES

描述：(直接取自应用)哺乳动物尿路上皮的顶端表面覆盖着许多看起来僵硬的斑块，由16纳米蛋白质颗粒的二维晶体组成。这些斑块也被称为不对称单位膜，是尿路上皮终末分化的结构标志，被认为在使尿路上皮发挥其生理功能方面发挥着中心功能，即充当高度不通透和灵活的屏障。然而，尿路上皮斑块究竟如何做到这一点还完全不清楚。目前也不清楚编码尿路上皮斑块蛋白亚基的基因是如何调节的，从而使它们以尿路上皮特异的和依赖于分化的方式表达。这些问题的答案对于我们理解尿路上皮在正常生理条件下的功能，以及尿路蛋白结构和基因调控的异常如何导致某些膀胱疾病至关重要。因此，该项目的长期目标是更准确地定义尿路上皮斑块的生物学功能，并从分子角度更好地了解尿路上皮蛋白基因是如何调控的。为了实现这些目标，我们将进行两个系列的实验，重点是基因的去除和调控：(1)通过同源重组破坏一些尿路蛋白基因，以产生尿路蛋白缺陷小鼠，并评估尿路上皮斑块的体内功能；(2)剖析一些尿路上皮蛋白基因的调控序列，以确定各种顺式基序在这些基因的组织特异性和分化依赖性表达中的作用。这些研究结果将有助于更好地了解Uroplakin基因的功能和调控，并可能为建立人类膀胱病的动物模型奠定基础。

Description: (Taken directly from the application) The apical surface of mammalian urothelium is covered with numerous rigid-looking plaques consisting of two dimensional crystals of 16-nm protein particles. These plaques, also known as the asymmetric unit membranes, are the structural hallmark of urothelial terminal differentiation and are presumed to play a central functional role in enabling the urothelium to perform its physiological function, i.e., to serve as a highly impermeable and flexible barrier. However, how precisely the urothelial plaques accomplish this is not at all clear. It is also unclear how the genes encoding the protein subunits of the urothelial plaques are regulated so that they are expressed in a urothelium-specific and differentiation-dependent fashion. Answers to these questions are crucially important for us to understand how urothelium functions in normal physiological conditions, and how abnormalities in uroplakin structure and gene regulation may give rise to certain bladder diseases. Therefore the long term goal of this project is to define more precisely the biological functions of urothelial plaques, and to better understand in molecular terms how the uroplakin genes are regulated. Towards these goals, we will perform two series of experiments focusing on the genetic abrogation and regulation of selected uroplakin genes: (1) To disrupt some of the uroplakin genes by homologous recombination in order to generate uroplakin-deficient mice and to assess the in vivo functions of urothelial plaques; and (2) To dissect the regulatory sequences of some of the uroplakin genes in order to determine the roles of various cis-motifs in the tissue-specific and differentiation-dependent expression of these genes. The results of these studies will lead to a better understanding of the function and regulation of uroplakin genes, and may give raise to animal models of human bladder diseases.