Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-3-1
pubmed:abstractText
The longstanding puzzle of membrane water permeability was advanced by the discovery of channel-forming integral protein (CHIP). This protein was shown to function as a water channel when expressed in Xenopus oocytes or when reconstituted into synthetic membranes. Site-directed mutagenesis and electron crystallography reveal tetrameric organization of CHIP, and the two halves of CHIP are tandem repeats folded into an obversely symmetric structure which resembles an hourglass. Each tetramer is comprised of functionally independent subunits. CHIP is the archetypal member of a newly-recognized family of membrane water transporters known as the "Aquaporins" (AQPs). AQP1 (CHIP) is abundant in the apical and basolateral membranes of renal proximal tubules and descending thin limbs, and is also present in a number of extra renal tissues. In the collecting duct, AQP2 is the predominant vasopressin-sensitive water channel. AQP2 is localized in the apical membrane and in intracellular vesicles which are targeted to the apical plasma membranes when stimulated by antidiuretic hormone. Humans are identified with mutations in AQP1 and AQP2 and exhibit contrasting clinical phenotypes. AQP3 resides in the basolateral membranes of collecting duct principal cells providing an exit pathway for water, and AQP4 is abundant in brain, where it apparently functions as the hypothalamic osmoreceptor responsible for secretion of antidiuretic hormone. Continued analysis of the aquaporins is providing detailed molecular insight into the fundamental physiological problems of water balance and water balance disorders.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0085-2538
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1057-68
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The aquaporin family of water channels in kidney.
pubmed:affiliation
Department of Cell Biology, University of Aarhus, Denmark.
pubmed:publicationType
Journal Article, Review