共 27 条
Serine 269 phosphorylated aquaporin-2 is targeted to the apical membrane of collecting duct principal cells
被引:112
作者:
Moeller, Hanne B.
[1
]
Knepper, Mark A.
[2
]
Fenton, Robert A.
[1
]
机构:
[1] Univ Aarhus, Inst Anat, Water & Salt Res Ctr, DK-8000 Aarhus, Denmark
[2] NHLBI, Kidney & Electrolyte Metab Lab, Natl Inst Hlth, Bethesda, MD 20892 USA
关键词:
phosphorylation;
vasopressin;
endocytosis;
exocytosis;
immunohistochemistry;
aquaporin water channel;
WATER CHANNEL;
VASOPRESSIN TREATMENT;
EPITHELIAL-CELLS;
PLASMA-MEMBRANE;
RAT-KIDNEY;
AQP2;
TRAFFICKING;
EXPRESSION;
PERMEABILITY;
ENDOCYTOSIS;
D O I:
10.1038/ki.2008.505
中图分类号:
R5 [内科学];
R69 [泌尿科学(泌尿生殖系疾病)];
学科分类号:
1002 ;
100201 ;
摘要:
Trafficking of the water channel aquaporin-2 to the apical plasma membrane of the collecting duct is mediated by arginine vasopressin, rendering the cell permeable to water. We recently identified a novel form of aquaporin-2 that is phosphorylated at serine-269 (pS269-AQP2). Using antibodies specific for this form of the water channel, we detected rat and mouse pS269-AQP2 in the connecting tubule and throughout the collecting duct system. Using confocal immunofluorescence microscopy with organelle-specific markers and immunogold electron microscopy, we found that pS269-AQP2 was found only on the apical plasma membrane of principal cells. In vasopressin-deficient Brattleboro rats, pS269-AQP2 was undetectable but dramatically increased in abundance after these rats were treated with [deamino-Cys-1, d-Arg8] vasopressin (dDAVP). This increase occurred only at the apical plasma membrane, even after long-term dDAVP treatment. Following dDAVP there was a time-dependent redistribution of total aquaporin-2 from predominantly intracellular vesicles to the apical plasma membrane, clathrin-coated vesicles, early endosomal compartments, and lysosomes. However, pS269-AQP2 was found only on the apical plasma membrane at any time. Our results show that S269 phosphorylated aquaporin-2 is exclusively associated with the apical plasma membrane, where it escapes endocytosis to remain at the cell surface.
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页码:295 / 303
页数:9
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