Diverse vasopressin V2 receptor functionality underlying partial congenital nephrogenic diabetes insipidus
Diverse vasopressin V2 receptor functionality underlying partial congenital nephrogenic diabetes insipidus
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DOI：
10.1152/ajprenal.00331.2009
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发表时间：
2009-12-01
影响因子：
4.2
通讯作者：
Corydon, Thomas J.
中科院分区：
文献类型：
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作者：
Faerch, Mia;Christensen, Jane H.;Corydon, Thomas J.
[10]杨文辉，杨文辉.部分先天性肾源性尿崩症的血管加压素V2受体功能多样性美国肾脏生理学杂志297：F1518-F1525，2009年。首次发表于2009年10月7日; doi：10.1152/ajprenal.00331.2009.- X-连锁先天性肾源性尿崩症（CNDI）的特征在于由于精氨酸加压素受体2（AVPR 2）基因的变异而引起的对抗利尿激素（AVP）的肾反应缺陷。在一组独特的患者中，肾脏对AVP作用的不敏感性是不完全的，导致部分表型。为了研究分子缺陷，在瞬时转染的人胚肾细胞中表达了已知引起部分CNDI表型的AVPR 2基因的两个先前发表的变异。一个变异（p.Arg104Cys）位于受体蛋白的第一胞外环，另一个变异（p.Ser329Arg）位于受体蛋白的胞内COOH末端。蛋白质印迹法显示稳定状态下WT-V2 R和Arg 104 Cys-V2 R蛋白的含量几乎相等，而Ser 329 Arg-V2 R蛋白的水平较低。共聚焦显微镜证实WT-V2 R和Arg 104 Cys-V2 R定位于细胞表面，而Ser 329 Arg-V2 R主要积聚在内质网内，导致表面表达减少。配体结合分析表明，表达Arg 104 Cys-V2 R和Ser 329 Arg-V2 R的细胞的B-max分别比WT-V2 R的B-max低14.8倍和2.5倍。AVP对WT-V2 R和Ser 329 Arg-V2 R的亲和力（1/K-d）相似，而对Arg 104 Cys-V2 R的亲和力（1/K-d）增加。cAMP测定显示，表达p. Arg 104 Cys-V2 R或p. Ser 329 Arg-V2 R的细胞产生的cAMP量分别比WT-V2 R低1.7倍和6.8倍。总之，配体结合和信号转导能力取决于氨基酸变异的定位。因此，在受体功能水平上的显著差异可能是CNDI中相似临床表型的基础。
Faerch M, Christensen JH, Rittig S, Johansson J-O, Gregersen N, de Zegher F, Corydon TJ. Diverse vasopressin V2 receptor functionality underlying partial congenital nephrogenic diabetes insipidus. Am J Physiol Renal Physiol 297: F1518-F1525, 2009. First published October 7, 2009; doi:10.1152/ajprenal.00331.2009.-X-linked congenital nephrogenic diabetes insipidus (CNDI) is characterized by a defective renal response to the antidiuretic hormone (AVP) due to variations in the arginine vasopressin receptor 2 (AVPR2) gene. In a unique group of patients, the renal insensitivity to the effects of AVP is incomplete resulting in a partial phenotype. To investigate the molecular defects, two previously published variations in the AVPR2 gene, known to cause a partial CNDI phenotype, were expressed in transiently transfected human embryonic kidney cells. One variation (p.Arg104Cys) is located in the first extracellular loop and the other variation (p.Ser329Arg) is located in the intracellular COOH terminal of the receptor protein. Western blotting showed almost equal amounts of WT-V2R and Arg104Cys-V2R protein at steady state, whereas the level of Ser329Arg-V2R protein was lower. Confocal microscopy established that WT-V2R and Arg104Cys-V2R are localized on the cellular surface while the Ser329Arg-V2R primarily accumulates within the endoplasmic reticulum resulting in reduced surface expression. Ligand binding analysis demonstrated that the B-max for cells expressing Arg104Cys-V2R and Ser329Arg-V2R were 14.8- and 2.5-fold lower than B-max for WT-V2R, respectively. AVP affinity (1/K-d) for WT-V2R and the Ser329Arg-V2R was similar while 1/K-d for Arg104Cys-V2R was increased. cAMP assay revealed that cells expressing p. Arg104Cys-V2R or p. Ser329Arg-V2R produced 1.7- and 6.8-fold lower amounts of cAMP compared with WT- V2R, respectively. In conclusion, ligand binding and signal transduction capability are dependent on localization of the amino acid variation. Striking divergences at the level of receptor functionality may thus underlie similar clinical phenotypes in CNDI.