A Skpl-containing Complex Regulating V-ATPase Activity

描述：（由申请人提供）极性H-+易位ATP酶 （V-ATP酶）是高度保守的酶，其在细胞中起核心作用， 生理学源于它们酸化细胞内区室的能力， 调节胞浆pH和钙浓度，并建立质子 驱动其他运输工具的梯度。这些功能可以适用于许多 不同的细胞环境，因此，V-ATP酶活性与 疾病状态多种多样，如病毒感染，代谢性酸中毒， 肾功能受损和骨质疏松Skp 1是一个高度保守的蛋白质 在泛素依赖的蛋白水解中起着重要作用， SCF E3泛素连接酶家族的成员，除了生长的 非蛋白水解作用的数量。SCF复合物对广泛的 磷酸化底物的阵列，从而与许多信号 转导途径最近，一种新的含有Skp 1的复合物RAVE被发现。 在酵母中鉴定，并显示含有另外两种未鉴定的蛋白质。 RAVE复合物似乎不是SCF泛素连接酶;相反，它 似乎在反应后调节V-ATP酶活性， 通过调节V-ATP酶的组装程度， 复杂.在这里提出的项目中，我们将使用酵母菌 酿酒酵母作为一个模型系统，以检查结构和功能的基础， 通过RAVE复合物调节V-ATP酶活性和组装。我们将 研究RAVE复合体的三个亚基如何相互作用， 与V-ATP酶的外周V1区连接。我们将决定 RAVE的蛋白组分直接受到细胞外 条件，以及这些变化如何影响与V1部门的互动。 我们将开发一个系统，用于监控RAVE和 V-ATP酶在体内，使用两种复合物的荧光衍生物。最后， 我们将探索RAVE对V-ATPase作用的分子基础， 外周和整体RAVE依赖性组装的体外模型 膜部分的ATP酶，并使用此模型系统来测试 假设RAVE辅助V1亚基之一的功能附着。

DESCRIPTION: (provided by applicant) Vacuolar H-+ translocating ATPases (V-ATPases) are highly conserved enzymes that play a central role in cell physiology stemming from their ability to acidify intracellular compartments, regulate cytosolic pH and calcium concentrations, and establish proton gradients that drive other transporters. These functions can be adapted to many different cellular contexts, and as a result, V-ATPase activity is linked to disease states as diverse as viral infection, metabolic acidosis due to impaired kidney function, and osteoporosis. Skp1 is a highly conserved protein that plays a central role in ubiquitin-dependent proteolysis as an essential member of the family of SCF E3 ubiquitin ligases in addition to a growing number of non-proteolytic roles. SCF complexes show specificity for a wide array of phosphorylated substrates and thus interact with many signal transductional pathways. Recently a new Skp1-containing complex, RAVE, was identified in yeast and shown to contain two other uncharacterized proteins. The RAVE complex does not appear to be an SCF ubiquitin ligase; instead, it appears to post-translationally regulate V-ATPase activity in response to extracellular conditions by modulating the extent of assembly of the V-ATPase complex. In the project proposed here, we will use the yeast Saccharomyces cerevisiae as a model system to examine the structural and functional basis for regulation of V-ATPase activity and assembly by the RAVE complex. We will examine how the three subunits of the RAVE complex interact with each other and with the peripheral V1 sector of the V-ATPase. We will determine whether protein components of RAVE are directly affected by changes in extracellular conditions, and how these changes might affect interaction with the V1 sector. We will develop a system for monitoring interactions between RAVE and the V-ATPase in vivo, using fluorescent derivatives of the two complexes. Finally, we will probe the molecular basis of RAVE action on the V-ATPase by developing an in vitro model for RAVE-dependent assembly of the peripheral and integral membrane sectors of the ATPase and using this model system to test the hypothesis that RAVE assists functional attachment of one of the V1 subunits.