1. Urea transport across an IMCD cell.
Urea transport across an IMCD cell. Vasopressin binds to the V2R, located on the basolateral plasma membrane, and activates the α subunit of the heterotrimeric G protein Gsα. Activation of the G protein stimulates AC to synthesize cAMP. The increase of intracellular cAMP stimulates several downstream proteins including PKA and Epac, which phosphorylate UT-A1 and increase its accumulation in the apical plasma membrane. Urea enters the IMCD cell through UT-A1 and exits on the basolateral plasma membrane via UT-A3. AC, adenylyl cyclase; Epac, exchange protein directly activated by cAMP; Gs, G protein stimulatory subunit; P, phosphate; PKA, protein kinase A; V2R, V2 vasopressin receptor. Modified from reference 13 with permission.
I. David Weiner et al. CJASN 2015;10:
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