Human Molecular Genetics Advance Access originally published online on October 27, 2004
Human Molecular Genetics 2004 13(24):3045-3056; doi:10.1093/hmg/ddh339
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Human Molecular Genetics, Vol. 13, No. 24 © Oxford University Press 2004; all rights reserved
A novel mechanism in recessive nephrogenic diabetes insipidus: wild-type aquaporin-2 rescues the apical membrane expression of intracellularly retained AQP2-P262L
1Department of Physiology, Radboud University of Nijmegen Medical Center, Nijmegen, The Netherlands, 2Department of Medicine, University of Montreal and Centre de Recherches, Hôpital du Sacre-Coeur de Montreal, Montreal, Quebec, Canada, 3Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands and 4Feinberg School of Medicine of Northwestern University, Chicago, IL, USA
Received June 14, 2004; Accepted October 19, 2004
Vasopressin regulates water homeostasis through insertion of homotetrameric aquaporin-2 (AQP2) water channels in the apical plasma membrane of renal cells. AQP2 mutations cause recessive and dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin. Until now, all AQP2 mutants in recessive NDI were shown to be misfolded, retained in the endoplasmic reticulum (ER) and unable to interact with wild-type (wt)-AQP2, whereas AQP2 mutants in dominant NDI are properly folded and interact with wt-AQP2, but, due to the mutation, cause missorting of the wt-AQP2/mutant complex. Here, patients of two families with recessive NDI appeared compound heterozygotes for AQP2-A190T or AQP2-R187C mutants, together with AQP2-P262L. As mutations in the AQP2 C-tail, where P262 resides, usually cause dominant NDI, the underlying cell-biological mechanism was investigated. Upon expression in oocytes, AQP2-P262L was a properly folded and functional aquaporin in contrast to the classical mutants, AQP2-R187C and AQP2-A190T. Expressed in polarized cells, AQP2-P262L was retained in intracellular vesicles and did not localize to the ER. Upon co-expression, however, AQP2-P262L interacted with wt-AQP2, but not with AQP2-R187C, resulting in a rescued apical membrane expression of AQP2-P262L. In conclusion, our study reveals a novel cellular phenotype in recessive NDI in that AQP2-P262L acts as a mutant in dominant NDI, except for that its missorting is overruled by apical sorting of wt-AQP2. Also, it demonstrates for the first time that the recessive inheritance of a disease involving a channel can be due to two cell-biological mechanisms.
* To whom correspondence should be addressed at: Department of Physiology, RUNMC, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Tel: +31 243617347; Fax: +31 243616413; Email: p.deen{at}ncmls.kun.nl
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P. M. T. Deen Mouse models for congenital nephrogenic diabetes insipidus: what can we learn from them? Nephrol. Dial. Transplant., April 1, 2007; 22(4): 1023 - 1026. [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Hoffert, J. Nielsen, M.-J. Yu, T. Pisitkun, S. M. Schleicher, S. Nielsen, and M. A. Knepper Dynamics of aquaporin-2 serine-261 phosphorylation in response to short-term vasopressin treatment in collecting duct Am J Physiol Renal Physiol, February 1, 2007; 292(2): F691 - F700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Robben, N. V. A. M. Knoers, and P. M. T. Deen Cell biological aspects of the vasopressin type-2 receptor and aquaporin 2 water channel in nephrogenic diabetes insipidus. Am J Physiol Renal Physiol, August 1, 2006; 291(2): F257 - F270. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. W. McDill, S.-Z. Li, P. A. Kovach, L. Ding, and F. Chen Congenital progressive hydronephrosis (cph) is caused by an S256L mutation in aquaporin-2 that affects its phosphorylation and apical membrane accumulation PNAS, May 2, 2006; 103(18): 6952 - 6957. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. M. Fujiwara and D. G. Bichet Molecular Biology of Hereditary Diabetes Insipidus J. Am. Soc. Nephrol., October 1, 2005; 16(10): 2836 - 2846. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. de Mattia, P. J.M. Savelkoul, E.-J. Kamsteeg, I. B.M. Konings, P. van der Sluijs, R. Mallmann, A. Oksche, and P. M.T. Deen Lack of Arginine Vasopressin-Induced Phosphorylation of Aquaporin-2 Mutant AQP2-R254L Explains Dominant Nephrogenic Diabetes Insipidus J. Am. Soc. Nephrol., October 1, 2005; 16(10): 2872 - 2880. [Abstract] [Full Text] [PDF]
|
|