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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2009-10-5
pubmed:abstractText
Regulation of body water homeostasis occurs by the vasopressin-dependent sorting of aquaporin-2 (AQP2) water channels to and from the apical membrane of renal principal cells. Mutations in AQP2 cause autosomal nephrogenic diabetes insipidus (NDI), a disease that renders the kidney unresponsive to vasopressin, resulting in polyuria and polydipsia. The AQP2 mutant c.772G>A; p.Glu258Lys (AQP2-E258K) causes dominant NDI by oligomerizing with wild-type AQP2 and missorting of this AQP2 complex to multivesicular bodies instead of the apical membrane. The motif causing this missorting of AQP2-E258K was identified here. Functional analyses and plasma membrane expression studies of truncation mutants in oocytes revealed that AQP2-E258K shortened to Leu259 is still intracellular retained. Alanine scanning and glutamic acid to arginine exchanges revealed increased function and plasma membrane expression for AQP2-E258K mutants with the following additional changes: Leu259Ala, Arg252Glu, Arg253Glu, or Arg252Ala-Arg254Ala, or for the AQP2 mutant p.Glu258Ala, indicating that the motif RRRxxxK(258)L confers AQP2-E258K retention. Fusion of this motif to aquaporin-1 also resulted in missorting of that water channel, indicating that this retention motif is transferable. In conclusion, our data reveal that the RRRxxxKL motif and repulsion between K258 and the arginine-triplet within this motif are the primary cause of missorting of AQP2-E258K in NDI.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1098-1004
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1387-96
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Repulsion between Lys258 and upstream arginines explains the missorting of the AQP2 mutant p.Glu258Lys in nephrogenic diabetes insipidus.
pubmed:affiliation
Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't