Identification of Rab3-, Rab5a- and synaptobrevin II-like proteins in a preparation of rat kidney vesicles containing the vasopressin-regulated water channel.
According to the 'shuttle hypothesis', vasopressin increases the water permeability of renal epithelial cells by exocytotic fusion of vesicles containing the water channel AQP-CD with the apical plasma membrane, whereas withdrawal of vasopressin results in endocytotic uptake of AQP-CD. The proteins involved in the redistribution of AQP-CD have not been identified. With a panel of monoclonal antibodies, we detected Rab3-, Rab5a- and synaptobrevin II-like proteins in a kidney preparation enriched in AQP-CD-containing vesicles. The synaptobrevin II-like proteins is not identical with the ubiquitous cellubrevin. Rab3- and synaptobrevin II- but not Rab5a-like proteins were co-enriched with AQP-CD. The data suggest that the proteins involved in hormonal regulation of water permeability in kidney epithelial cells are identical or similar to those involved in regulated exocytosis in secretory cells.
Liebenhoff
U
U
Rudolf-Buchheim-Institut für Pharmakologie, Justus-Liebig-Universität Giessen, Germany.
Rosenthal
W
W
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins; D004591:Electrophoresis, Polyacrylamide Gel; D004705:Endocytosis; D004848:Epithelium / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000032:analysis; D019204:GTP-Binding Proteins / Q000032:analysis* / Q000302:isolation & purification; D007106:Immune Sera; D015151:Immunoblotting; D007473:Ion Channels / Q000032:analysis* / Q000302:isolation & purification; D007679:Kidney Medulla / Q000378:metabolism*; D008565:Membrane Proteins / Q000032:analysis* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000302:isolation & purification; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D050683:R-SNARE Proteins; D051381:Rats; D014667:Vasopressins / Q000502:physiology*; D020692:rab3 GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins
D000906:Antibodies; C496025:Aqp2 protein, rat; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins; D007106:Immune Sera; D007473:Ion Channels; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; D050683:R-SNARE Proteins; D014667:Vasopressins; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins; D020696:rab5 GTP-Binding Proteins