MODULATION AND REGULATION OF ROMK CHANNELS IN KIDNEY

描述：（申请书逐字逐句）提案的总体目标 (IRPG#3）是探索ROMK激素调节的分子机制 并确定ROMK通道在形成顶端K +通道中的作用 在厚上升支（TAL）中。ROMK通道共享关键的生物物理 天然小电导ATP敏感性K+通道（SKatp） 在TAL和集合管中。然而，调节SKstp的机制 由于SKatp的密度低，TAL中的蛋白质还没有完全了解。 这一困难现在可以克服，因为初步结果表明， 在小鼠TAL中，顶端K通道的密度显着增加 通过添加毛喉素或去除细胞外Ca 2+增加。 因此，具体目标1的第一个目标是研究生物物理特性 的顶端K+通道的小鼠TAL。这些信息很重要 为了进一步研究ROMK通道在形成顶端K+中的作用， 当ROMK敲除小鼠可用时，第二个目标是 探索加压素受体与 Ca2+敏感受体（CaR）介导的作用在确定 小鼠TAL中顶端K+通道的活性。 具体目标2的目标是研究激酶锚定蛋白的作用 介导PKA和PKC调节ROMK通道功能的作用， 磷酸化具体目标3的目标是通过以下方式研究机制： 其中PGE2调节TAL中的顶端K+通道。PGE2的作用 与Bartter综合征的相关性，其中高肾上腺素血症突出， 抑制前列腺素的产生部分逆转了 TAL功能受损的后果。

DESCRIPTION: (verbatim from application) The overall goals of the proposal (IRPG#3) are to explore the molecular mechanisms of hormonal regulation of ROMK channels and to define the role of ROMK channels in forming apical K + channels in the thick ascending limb (TAL). ROMK channels share the key biophysical properties with the native small-conductance ATP-sensitive K+ channel (SKatp) in the TAL and collecting duct. However, mechanisms by which SKstp is regulated in the TAL are not completely understood since the density of the SKatp is low. This difficulty can now be overcome since preliminary results have demonstrated that in the mouse TAL the density of the apical K channels is significantly increased by either adding forskolin or removal of extracellular Ca2+. Thus, the first goal of Specific Aim 1 is to study the biophysical properties of the apical K+ channels in the mouse TAL. The information will be important for further studying the role of ROMK channels in forming the apical K+ channels when the ROMK‑knockout mice are available. The second goal is to explore the hypothesis that interaction between the vasopressin receptor and the Ca2+-sensing receptor (CaR)-mediated action plays a key role in determining the activity of the apical K+ channels in the mouse TAL. The goal of Specific Aim 2 is to examine the role of kinase anchoring proteins in mediating the effect of PKA and PKC in modulating ROMK channel function and phosphorylation. The goal of Specific Aim 3 is to investigate the mechanism by which PGE2 regulates the apical K+ channels in the TAL. The effect of PGE2 has relevance to Bartter's Syndrome where hyperprostaglandinemia is prominent and inhibition of prostaglandin production reverses partially the physiological consequences of impaired TAL function.