Angiotensin II stimulates elution of Na-K-ATPase from a digoxin-affinity column by increasing the kinetic response to ligands that trigger the decay of E2-P.
Angiotensin II stimulates elution of Na-K-ATPase from a digoxin-affinity column by increasing the kinetic response to ligands that trigger the decay of E2-P.
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血管紧张素 II 通过增加对触发 E2-P 衰变的配体的动力学响应，刺激 Na-K-ATP 酶从地高辛亲和柱中洗脱。
DOI：
10.1152/ajprenal.00492.2007
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Mattingly,RaymondR
中科院分区：
文献类型：
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作者：
Yingst,DouglasR;Doci,TabithaM;Massey,KatherineJ;Rossi,NoreenF;Rucker,Ebony;Mattingly,RaymondR
我们早期观察到，用直接刺激Na-K-ATP酶活性的浓度的血管紧张素II（ANG II）处理大鼠近端小管改变了Na-K-ATP酶随后从哇巴因亲和柱洗脱的方式。在这项研究中，我们测试了ANG II是否增加洗脱速率以响应触发E2-P衰减的配体，这意味着Na-K-ATP酶功能特性的变化，或者通过减少随后用SDS洗脱的量，这表明Na-K-ATP酶如何与其他蛋白质相互作用的变化。我们利用了一种新的地高辛亲和柱和新的负鼠肾（OK）细胞系，这些细胞系共表达大鼠AT 1a受体和野生型大鼠α1-亚型Na-K-ATP酶或缺失其NH 2末端前32个氨基酸的截短突变体。我们描述了大鼠肾微粒体如何与地高辛亲和柱结合并从地高辛亲和柱上洗脱，并证明了它们在释放地高辛以响应触发E2-P衰减的配体的速率上是不均匀的。用ANG II孵育OK细胞通过增加对引起E2-P衰减的配体的动力学响应来刺激随后的野生型大鼠α1亚基洗脱。P而不影响随后用SDS洗脱的量。相反，ANG II对截断突变体的动力学响应没有影响，但降低了用SDS洗脱的量。这些数据表明，ANG Ⅱ通过其NH 2末端调节Na-K-ATP酶的动力学特性及其与其他蛋白质的相互作用。
We earlier observed that treating rat proximal tubules with concentrations of angiotensin II (ANG II) that directly stimulate Na-K-ATPase activity changed how Na-K-ATPase subsequently eluted from an ouabain-affinity column. In this study we tested whether ANG II increases the rate of elution in response to ligands that trigger the decay of E2-P, which implies a change in functional properties of Na-K-ATPase, or by decreasing the amount subsequently eluted with SDS, which suggests a change in how Na-K-ATPase interacts with other proteins. We utilized a new digoxin-affinity column and novel lines of opossum kidney (OK) cells that coexpress the rat AT1areceptor and either the wild-type rat α1-isoform of Na-K-ATPase or a truncation mutant missing the first 32 amino acids of its NH2terminus. We characterized how rat kidney microsomes bind to and elute from the digoxin-affinity column and demonstrated that they are heterogeneous in the rate at which they release digoxin in response to ligands that trigger the decay of E2-P. Incubating OK cells with ANG II stimulated the ensuing elution of wild-type rat α1-subunit by increasing the kinetic response to ligands that cause a decay of E2-P without affecting the amount later eluted with SDS. In contrast, ANG II had no effect on the kinetic response of the truncation mutant but decreased the amount eluted with SDS. These data suggest that ANG II regulates both the kinetic properties of Na-K-ATPase and its interaction with other proteins by a mechanism(s) involving its NH2terminus.