Parathyroid hormone activates TRPV5 via PKA-dependent phosphorylation

J Am Soc Nephrol. 2009 Aug;20(8):1693-704. doi: 10.1681/ASN.2008080873. Epub 2009 May 7.


Low extracellular calcium (Ca(2+)) promotes release of parathyroid hormone (PTH), which acts on multiple organs to maintain overall Ca(2+) balance. In the distal part of the nephron, PTH stimulates active Ca(2+) reabsorption via the adenylyl cyclase-cAMP-protein kinase A (PKA) pathway, but the molecular target of this pathway is unknown. The transient receptor potential vanilloid 5 (TRPV5) channel constitutes the luminal gate for Ca(2+) entry in the distal convoluted tubule and has several putative PKA phosphorylation sites. Here, we investigated the effect of PTH-induced cAMP signaling on TRPV5 activity. Using fluorescence resonance energy transfer, we studied cAMP and Ca(2+) dynamics during PTH stimulation of HEK293 cells that coexpressed the PTH receptor and TRPV5. PTH increased cAMP levels, followed by a rise in TRPV5-mediated Ca(2+) influx. PTH (1 to 31) and forskolin, which activate the cAMP pathway, mimicked the stimulation of TRPV5 activity. Remarkably, TRPV5 activation was limited to conditions of strong intracellular Ca(2+) buffering. Cell surface biotinylation studies demonstrated that forskolin did not affect TRPV5 expression on the cell surface, suggesting that it alters the single-channel activity of a fixed number of TRPV5 channels. Application of the PKA catalytic subunit, which phosphorylated TRPV5, directly increased TRPV5 channel open probability. Alanine substitution of threonine-709 abolished both in vitro phosphorylation and PTH-mediated stimulation of TRPV5. In summary, PTH activates the cAMP-PKA signaling cascade, which rapidly phosphorylates threonine-709 of TRPV5, increasing the channel's open probability and promoting Ca(2+) reabsorption in the distal nephron.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / metabolism*
  • Calcium Signaling*
  • Cell Line
  • Colforsin
  • Cyclic AMP / metabolism
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Parathyroid Hormone / metabolism*
  • Phosphatidylinositol 4,5-Diphosphate / metabolism
  • Phosphorylation
  • Receptor, Parathyroid Hormone, Type 1 / metabolism
  • TRPV Cation Channels / metabolism*
  • Threonine


  • PTH1R protein, human
  • Parathyroid Hormone
  • Phosphatidylinositol 4,5-Diphosphate
  • Receptor, Parathyroid Hormone, Type 1
  • TRPV Cation Channels
  • TRPV5 protein, human
  • Colforsin
  • Threonine
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • Calcium