REGULATION OF THE SODIUM CHLORIDE COTRANSPORTER

描述（由申请人提供）：我的最终目标是成为一名完全独立的首席研究员，在基础科学实验室研究肾离子运输的分子生理学。在3个不同的机构跟随史蒂芬·赫伯特博士完成了6年的培训后，我成为了芝加哥大学的助理教授。这段时间我一直在研究大鼠噻嗪类敏感氯化钠共转运体（rNCC）的糖基化和磷酸化调控。我已经证明rNCC能够在体外被PKC磷酸化，rNCC在功能上受到PKC的抑制，并且随着PKC一致磷酸化位点的突变，rNCC的基线功能和表面表达显著增加。在职业发展奖、芝加哥大学医学系以及我的导师Herbert博士和Chang博士的支持下，我希望能继续朝着我的长期目标前进。NCC是最常用的抗高血压药物之一的作用部位，在二价阳离子处理中起着关键作用，但我们对其调控知之甚少。这一提议将验证PKC和WNK4激酶在NCC调控中发挥关键作用的假设，主要是通过丝氨酸和苏氨酸残基的磷酸化导致表面表达减少。第一个具体目标将寻求确定WNK4激酶、PKC和PKA在调节NCC活性和表面表达中的作用和机制。第二个具体目标将寻求探索共转运体和激酶的生理和激素调节，共转运体在二价离子处理中的生理作用以及这些过程的机制。这项对血压和钙稳态效应调节的研究将为这些稳态机制失调的发病机制提供宝贵的见解。

DESCRIPTION (provided by applicant): My ultimate goal is to become a fully independent principal investigator with a basic science laboratory examining the molecular physiology of renal ion transport. After completing 6 years of training with Dr. Steven Herbert at 3 different institutions, I became an Assistant Professor at the University of Chicago. I have studied the regulation of the rat thiazide-sensitive sodium chloride cotransporter (rNCC) by glycosylation and phosphorylation for that period of time. I have demonstrated that rNCC is capable of being PKC phosphorylated in vitro, rNCC is functionally inhibited by PKC and there is a significant increase in baseline function and surface expression of rNCC with mutation of consensus PKC phosphorylation sites. With the support of this Career Development Award, the University of Chicago Department of Medicine, and my mentors, Dr. Herbert and Dr. Chang, I hope to continue to progress towards my long term goal. NCC is the site of action of one of the most commonly prescribed anti-hypertensive medications and plays a key role in divalent cation handling, yet we know little about it's regulation. This proposal will test the hypothesis that PKC and WNK4 kinase play a key role in regulation of NCC, predominantly by phosphorylation of serine and threonine residues resulting in decreased surface expression. The first specific aim will seek to define the role and mechanisms of WNK4 kinase, PKC and PKA in regulating the activity and surface expression of NCC. The second specific aim will seek to explore the physiological and hormonal regulation of the cotransporter and kinases, the physiological role of the cotransporter in divalent ion handling and the mechanisms underlying these processes. This investigation of the regulation of this effector of blood pressure and calcium homeostasis will provide invaluable insight into the pathogenesis of dysregulation of these homeostatic mechanisms.