Vasopressin regulation of multisite phosphorylation of UT-A1 in the inner medullary collecting duct
| Autor: | Diane L. Gumina, Lauren N. Black, Carol A. Hoban, Mitsi A. Blount, Ronald J. Ordas, Fadi E. Pulous, Jae H. Sim, Jeff M. Sands |
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| Rok vydání: | 2015 |
| Předmět: |
inorganic chemicals
Male Vasopressin medicine.medical_specialty Vasopressins Physiology Urea transporter macromolecular substances environment and public health Cell Line Rats Sprague-Dawley Internal medicine Cyclic AMP medicine Animals Kidney Tubules Collecting Phosphorylation biology Membrane transport protein Membrane Transport Proteins Articles Apical membrane Cyclic AMP-Dependent Protein Kinases enzymes and coenzymes (carbohydrates) Endocrinology Urea transport biology.protein bacteria cAMP-dependent pathway Intracellular |
| Zdroj: | American Journal of Physiology-Renal Physiology. 308:F49-F55 |
| ISSN: | 1522-1466 1931-857X |
| DOI: | 10.1152/ajprenal.00642.2013 |
| Popis: | Vasopressin signaling is critical for the regulation of urea transport in the inner medullary collecting duct (IMCD). Increased urea permeability is driven by a vasopressin-mediated elevation of cAMP that results in the direct phosphorylation of urea transporter (UT)-A1. The identification of cAMP-sensitive phosphorylation sites, Ser486 and Ser499, in the rat UT-A1 sequence was the first step in understanding the mechanism of vasopressin action on the phosphorylation-dependent modulation of urea transport. To investigate the significance of multisite phosphorylation of UT-A1 in response to elevated cAMP, we used highly specific and sensitive phosphosite antibodies to Ser486 and Ser499 to determine cAMP action at each phosphorylation site. We found that phosphorylation at both sites was rapid and sustained. Furthermore, the rate of phosphorylation of the two sites was similar in both mIMCD3 cells and rat inner medullary tissue. UT-A1 localized to the apical membrane in response to vasopressin was phosphorylated at Ser486 and Ser499. We confirmed that elevated cAMP resulted in increased phosphorylation of both sites by PKA but not through the vasopressin-sensitive exchange protein activated by cAMP pathway. These results elucidate the multisite phosphorylation of UT-A1 in response to cAMP, thus providing the beginning of understanding the intracellular factors underlying vasopressin stimulation of urea transport in the IMCD. |
| Databáze: | OpenAIRE |
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