Document Detail


A new kindred with pseudohypoaldosteronism type II and a novel mutation (564D>H) in the acidic motif of the WNK4 gene.
MedLine Citation:
PMID:  15998707     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We identified a new kindred with the familial syndrome of hypertension and hyperkalemia (pseudohypoaldosteronism type II or Gordon's syndrome) containing an affected father and son. Mutation analysis confirmed a single heterozygous G to C substitution within exon 7 (1690G>C) that causes a missense mutation within the acidic motif of WNK4 (564D>H). We confirmed the function of this novel mutation by coexpressing it in Xenopus oocytes with either the NaCl cotransporter (NCCT) or the inwardly rectifying K-channel (ROMK). Wild-type WNK4 inhibits 22Na+ flux in Xenopus oocytes expressing NCCT by approximately 90% (P<0.001), whereas the 564D>H mutant had no significantly inhibitory effect on flux through NCCT. In oocytes expressing ROMK, wild-type WNK4 produced >50% inhibition of steady-state current through ROMK at a +20-mV holding potential (P<0.001). The 564D>H mutant produced further inhibition with steady-state currents to some 60% to 70% of those seen with the wild-type WNK4. Using fluorescent-tagged NCCT (enhanced cyan fluorescent protein-NCCT) and ROMK (enhanced green fluorescent protein-ROMK) to quantify the expression of the proteins in the oocyte membrane, it appears that the functional effects of the 564D>H mutation can be explained by alteration in the surface expression of NCCT and ROMK. Compared with wild-type WNK4, WNK4 564D>H causes increased cell surface expression of NCCT but reduced expression of ROMK. This work confirms that the novel missense mutation in WNK4, 564D>H, is functionally active and highlights further how switching charge on a single residue in the acid motif of WNK4 affects its interaction with the thiazide-sensitive target NCCT and the potassium channel ROMK.
Authors:
Amir P Golbang; Meena Murthy; Abbas Hamad; Che-Hsiung Liu; Georgina Cope; William Van't Hoff; Alan Cuthbert; Kevin M O'Shaughnessy
Related Documents :
15713657 - Embryonic poly(a)-binding protein stimulates translation in germ cells.
16325797 - Possible role of mouse poly(a) polymerase mgld-2 during oocyte maturation.
9499577 - Linker histone transitions during mammalian oogenesis and embryogenesis.
19144907 - A bioinformatics search pipeline, rna2dsearch, identifies rna localization elements in ...
9142867 - Telokin expression in a10 smooth muscle cells requires serum response factor.
7204367 - Probable nuclear precursors of preprolactin mrna in rat pituitary cells.
Publication Detail:
Type:  Case Reports; Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-07-05
Journal Detail:
Title:  Hypertension     Volume:  46     ISSN:  1524-4563     ISO Abbreviation:  Hypertension     Publication Date:  2005 Aug 
Date Detail:
Created Date:  2005-07-29     Completed Date:  2005-11-29     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  United States    
Other Details:
Languages:  eng     Pagination:  295-300     Citation Subset:  IM    
Affiliation:
Clinical Pharmacology Unit, University of Cambridge, United Kingdom.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Amino Acid Motifs
Animals
Aspartic Acid
Cell Membrane / metabolism
Female
Genetic Testing
Histidine
Humans
Hyperkalemia / etiology
Hypertension / etiology
Male
Mutation, Missense*
Oocytes / metabolism
Pedigree
Potassium Channels, Inwardly Rectifying / metabolism
Protein-Serine-Threonine Kinases / genetics*
Pseudohypoaldosteronism / complications,  genetics*,  physiopathology
Receptors, Drug / metabolism
Sodium Chloride Symporters / metabolism
Sodium Radioisotopes / pharmacokinetics
Xenopus laevis
Chemical
Reg. No./Substance:
0/KCNJ1 protein, human; 0/Potassium Channels, Inwardly Rectifying; 0/Receptors, Drug; 0/Sodium Chloride Symporters; 0/Sodium Radioisotopes; 0/thiazide receptor; 56-84-8/Aspartic Acid; 71-00-1/Histidine; EC 2.7.11.1/Protein-Serine-Threonine Kinases; EC 2.7.11.1/WNK4 protein, human
Comments/Corrections
Comment In:
Hypertension. 2005 Aug;46(2):263-4   [PMID:  15998705 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Differing effects of mineralocorticoid receptor-dependent and -independent potassium-sparing diureti...
Next Document:  North American ginseng exerts a neutral effect on blood pressure in individuals with hypertension.