CELLULAR BIOLOGY OF RENAL FUNCTION AND DISEASE

在本计划项目的最初任期内，研究提供了 对加压素敏感物质的贩运和功能的新见解 水通道--细胞骨架在细胞调控中的作用 结构和功能，囊泡内吞和胞吐的调节，以及 肾上皮细胞功能极性的产生及其作用 钙和磷脂在信号转导中的作用。利用小说 我们在过去四年里开发的工具和细胞系统， 项目7现在将描述特化的早期内体小泡的特征 内化后叶加压素诱导的水通道，定义细胞 它们的生物循环，并最终隔离水道 它本身。项目8将利用一种独特的黑色素瘤细胞系 缺乏肌动蛋白结合蛋白(ABP)，无法调节离子通道 而且不能调节音量。这些功能可以通过以下方式完全恢复 将ABP基因导入细胞，这些细胞提供了强大的 一种检查细胞骨架和细胞之间相互作用的系统 与肾上皮细胞有关的膜功能。项目9将 探讨上皮细胞分泌和膜蛋白的调节 高尔基地区的人口贩运。它将利用我们新开发的 转异三聚体GTP诱导基因的肾细胞系 结合蛋白α亚基来继续我们的新发现 蛋白质与单体G蛋白协同作用调节高尔基体 堵车。项目10将研究微管的作用及其 相关蛋白质，MAP，参与极化的产生 上皮细胞表型。它将定义串扰的要求 在这一过程中微管和肌动蛋白调节蛋白之间的相互作用。 项目11将定义细胞内分类和极化目标 MHC I.该项目利用混合MHC构建， 肾上皮细胞系及其结构域和构象特异性 抗体用于研究一种“乘客”蛋白对人类免疫功能的影响 贩卖水泡。最后，项目6将继续阐明Ca++ 以及与激素信号转导有关的磷脂代谢 肾小球系膜细胞增殖。重点将是 赋予肌动蛋白以前未被认识到的重要作用- 磷脂代谢中的调节蛋白。和过去一样，这次 计划项目汇集了一群科学家，他们具有相当大的 在细胞生物学，分子生物学，生物物理学， 生物化学和形态学将使我们能够在更大的 肾细胞质膜和细胞质的深度相互作用 在正常功能和疾病中都很重要的细胞。

During the initial tenure of this Program Project, studies have provided new insights into the trafficking and function of the vasopressin-sensitive water channel, the role of the cytoskeleton in the modulation of cell structure and function, the regulation of vesicle endo- and exocytosis and the generation of functional polarity in kidney epithelia, and the role of Ca++ and phospholipids in signal transduction. Taking advantage of novel tools and cell systems that we have developed over the past four years, Project 7 will now characterize the specialized early endosomal vesicles that internalize vasopressin-induced water channels, define the cell biology of their recycling, and eventually isolate the water channel itself. Project 8 will utilize a unique melanoma cell line that is deficient in actin binding protein (ABP), fails to modulate ion channels and cannot volume-regulate. These functions can be totally restored by transfecting the cells with ABP cDNA, and these cells provide a powerful system in which to examine interactions between the cytoskeleton and membrane function that are relevant to renal epithelia. Project 9 will investigate the regulation of epithelial secretory and membrane protein trafficking in the Golgi. It will take advantage of our newly-developed renal cell lines transfected with inducible genes for heterotrimeric GTP- binding protein alpha subunits to pursue our novel discovery that these proteins work in concert with monomeric G-proteins to regulate Golgi traffic. Project 10 will examine the role of microtubules and their associated proteins, MAPs, involved in the generation of the polarized epithelial cell phenotype. It will define the requirement for cross-talk between microtubule- and actin-regulatory proteins in this process. Project 11 will define the intracellular sorting and polarized targeting of MHC I. This project take advantage of hybrid MHC constructs, transfected kidney epithelial cell lines, and domain and conformation-specific antibodies to investigate the contribution of a "passenger" protein in vesicle trafficking. Finally, Project 6 will continue to elucidate Ca++ and phospholipid metabolism as they relate to hormonal signal transduction and cell proliferation in glomerular mesangial cells. Emphasis will be placed on the important and previously unappreciated role of actin- regulatory proteins in phospholipid metabolism. As in the past, this Program Project brings together a group of scientists with considerable expertise in many aspects of cell biology, molecular biology, biophysics, biochemistry and morphology which will enable us to examine in greater depth interactions between the plasma membrane and the cytoplasm of renal cells that are important both in normal function and in disease.