Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
1998-9-24
pubmed:abstractText
Vasopressin is the key regulator of water homeostasis in vertebrates. Central to its antidiuretic action in mammals is the redistribution of the water channel aquaporin 2 (AQP2) from intracellular vesicles to the apical membrane of kidney epithelial cells, an event initiated by an increase in cAMP and activation of protein kinase A. The subsequent steps of the signaling cascade are not known. To identify proteins involved in the AQP2 shuttle we exploited a recently developed cell line (CD8) derived from the rabbit cortical collecting duct and stably transfected with rat AQP2 cDNA. Treatment of CD8 cells with pertussis toxin (PTX) inhibited both the vasopressin-induced increase in water permeability and the redistribution of AQP2 from an intracellular compartment to the apical membrane. ADP-ribosylation studies revealed the presence of at least two major PTX substrates. Correspondingly, two alpha subunits of PTX-sensitive G proteins, Galphai2 and Galphai3, were identified by Western blotting. Introduction of a synthetic peptide corresponding to the C terminus of the Gi3 alpha subunit into permeabilized CD8 cells efficiently inhibited the cAMP-induced AQP2 translocation; a peptide corresponding to the alpha subunits of Gi1/2 was much less potent. Thus a member of the Gi family, most likely Gi3, is involved in the cAMP-triggered targeting of AQP2-bearing vesicles to the apical membrane of kidney epithelial cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22627-34
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9712891-Amino Acid Sequence, pubmed-meshheading:9712891-Animals, pubmed-meshheading:9712891-Aquaporin 2, pubmed-meshheading:9712891-Aquaporin 6, pubmed-meshheading:9712891-Aquaporins, pubmed-meshheading:9712891-Biological Transport, pubmed-meshheading:9712891-Cell Line, pubmed-meshheading:9712891-Cyclic AMP, pubmed-meshheading:9712891-DNA, Complementary, pubmed-meshheading:9712891-Epithelial Cells, pubmed-meshheading:9712891-Forskolin, pubmed-meshheading:9712891-GTP-Binding Proteins, pubmed-meshheading:9712891-Ion Channels, pubmed-meshheading:9712891-Kidney Tubules, Collecting, pubmed-meshheading:9712891-Microscopy, Confocal, pubmed-meshheading:9712891-Microscopy, Fluorescence, pubmed-meshheading:9712891-Pertussis Toxin, pubmed-meshheading:9712891-Rabbits, pubmed-meshheading:9712891-Rats, pubmed-meshheading:9712891-Virulence Factors, Bordetella
pubmed:year
1998
pubmed:articleTitle
A heterotrimeric G protein of the Gi family is required for cAMP-triggered trafficking of aquaporin 2 in kidney epithelial cells.
pubmed:affiliation
Dipartimento di Fisiologia Generale e Ambientale, Universitá degli Studi, 70126 Bari, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't