Modulation of vasopressin-elicited water transport by trafficking of aquaporin2-containing vesicles.
Vasopressin or AVP regulates water reabsorption by the kidney inner medullary collecting duct (IMCD) through the insertion and removal of aquaporin (AQP) 2 water channels into the IMCD apical membrane. AVP-elicited trafficking of AQP2 with the apical membrane occurs via a specialized population of vesicles that resemble synaptic vesicles in neurons. AQP2 vesicles and the IMCD apical membrane contain homologs of vesicle-targeting and signal transduction proteins found in neurons. Expression studies of AQP2, including human AQP2 mutants, suggest that the carboxyl-terminal domain of AQP2 is important in AQP2 trafficking, particularly as a site for cAMP-dependent protein kinase phosphorylation. These present data reveal that IMCD cells possess a complex integrated-signaling and vesicle-trafficking machinery that provides integration of AVP-elicited water transport with many other parameters within the IMCD cell as well as kidney.
Ward
D T
DT
Division of Nephrology, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Hammond
T G
TG
Harris
H W
HW
D000818:Animals; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins / Q000378:metabolism*; D001127:Arginine Vasopressin / Q000494:pharmacology; D001692:Biological Transport / Q000502:physiology; D006801:Humans; D007679:Kidney Medulla; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014667:Vasopressins / Q000502:physiology*; D014867:Water / Q000378:metabolism*
C496023:AQP2 protein, human; D051399:Aquaporin 2; D051403:Aquaporin 6; D020346:Aquaporins; D014867:Water; D014667:Vasopressins; D001127:Arginine Vasopressin