Vasopressin regulation of the renal UT-A3 urea transporter.
Facilitative urea transporters in the mammalian kidney play a vital role in the urinary concentrating mechanism. The urea transporters located in the renal inner medullary collecting duct, namely UT-A1 and UT-A3, are acutely regulated by the antidiuretic hormone vasopressin. In this study, we investigated the vasopressin regulation of the basolateral urea transporter UT-A3 using an MDCK-mUT-A3 cell line. Within 10 min, vasopressin stimulates urea flux through UT-A3 transporters already present at the plasma membrane, via a PKA-dependent process. Within 1 h, vasopressin significantly increases UT-A3 localization at the basolateral membrane, causing a further increase in urea transport. While the basic trafficking of UT-A3 to basolateral membranes involves both protein kinase C and calmodulin, its regulation by vasopressin specifically occurs through a casein kinase II-dependent pathway. In conclusion, this study details the effects of vasopressin on UT-A3 urea transporter function and hence its role in regulating urea permeability within the renal inner medullary collecting duct.
Stewart
G S
GS
Faculty of Life Sciences, Core Technology Facility, University of Manchester, Manchester, United Kingdom.
Thistlethwaite
A
A
Lees
H
H
Cooper
G J
GJ
Smith
Craig
C
D000818:Animals; D047390:Casein Kinase II / Q000378:metabolism*; D002460:Cell Line; D004285:Dogs; D007668:Kidney / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D014508:Urea / Q000378:metabolism*; D014667:Vasopressins / Q000378:metabolism*; D000096982:Urea Transporters
D047390:Casein Kinase II; D026901:Membrane Transport Proteins; D014508:Urea; D014667:Vasopressins; D000096982:Urea Transporters