ROMK CHANNEL FUNCTION AND REGULATION IN KIDNEY

我们的研究项目将集中于探索有关肾脏钾（K+）通道（ROMK）调节的未解决问题。肾脏通过平衡肾小管上皮细胞的钾分泌和远端肾单位的闰细胞的钾重吸收，在钾稳态中起主要作用。在通过Na-K+ ATP酶主动摄取钾穿过基底外侧膜之后，通过低电导钾通道发生穿过主细胞顶膜的扩散。这些通道已被克隆，我们建议探索其调节机制。将追求两个主要目标。首先，我们建议探索激酶，pH和磷脂，以及通道亚基的化学计量的核苷酸依赖性通道门控的调节。其次，由于最近的研究已经确定了ROMK缺失巴特综合征，肾钠（Na）和K+消耗的条件，我们计划研究的影响，顶端钾通道的损失在ROMK敲除但模型。 我们还将研究K+分泌的替代运输机制。将在天然小管和卵母细胞表达系统中进行膜片钳和全细胞电流测量，并在ROMK敲除小鼠中进行小管灌注研究。

Our research project will focus on the exploration of unresolved problems concerning the regulation of renal potassium (K+) channels (ROMK). The kidney plays a major role in potassium homeostasis by a balance between potassium secretion in principal tubule cells and potassium reabsorption in intercalated cells of the distal nephron. Following active uptake of potassium across the basolateral membrane by Na-K+ ATPase, diffusion across the apical membrane of principal cells occurs via low-conductance potassium channels. These channels have been cloned and we propose to explore the mechanism of their regulation. Two major goals will be pursued. First, we propose to explore the regulation of nucleotidedependent channel gating by kinases, pH and phospolipids, and the stoichiometry of channel subunits. Second, because recent studies have identified ROMK deletions in Bartter's syndrome, a condition of renal sodium (Na) and K+ wasting, we plan to study the effects of loss of apical potassium channels in a ROMK knock-but model. We will also examine alternative transport mechanisms of K+ secretion. Patch-clamp and whole-cell current measurements will be carried out in native tubules and in an oocyte expression system, and tubule perfusion studies in ROMK knock-out mice.