β1-Adrenergic receptor signaling activates the epithelial calcium channel, transient receptor potential vanilloid type 5 (TRPV5), via the protein kinase A pathway.
Epinephrine and norepinephrine are present in the pro-urine. β-Adrenergic receptor (β-AR) blockers administered to counteract sympathetic overstimulation in patients with congestive heart failure have a negative inotropic effect, resulting in reduced cardiac contractility. Positive inotropes, β1-AR agonists, are used to improve cardiac functions. Active Ca(2+) reabsorption in the late distal convoluted and connecting tubules (DCT2/CNT) is initiated by Ca(2+) influx through the transient receptor potential vanilloid type 5 (TRPV5) Ca(2+) channel. Although it was reported that β-ARs are present in the DCT2/CNT region, their role in active Ca(2+) reabsorption remains elusive. Here we revealed that β1-AR, but not β2-AR, is localized with TRPV5 in DCT2/CNT. Subsequently, treatment of TRPV5-expressing mouse DCT2/CNT primary cell cultures with the β1-AR agonist dobutamine showed enhanced apical-to-basolateral transepithelial Ca(2+) transport. In human embryonic kidney (HEK293) cells, dobutamine was shown to stimulate cAMP production, signifying functional β1-AR expression. Fura-2 experiments demonstrated increased activity of TRPV5 in response to dobutamine, which could be prevented by the PKA inhibitor H89. Moreover, nonphosphorylable T709A-TRPV5 and phosphorylation-mimicking T709D-TRPV5 mutants were unresponsive to dobutamine. Surface biotinylation showed that dobutamine did not affect plasma membrane abundance of TRPV5. In conclusion, activation of β1-AR stimulates active Ca(2+) reabsorption in DCT2/CNT; an increase in TRPV5 activity via PKA phosphorylation of residue Thr-709 possibly plays an important role. These data explicate a calciotropic role in addition to the inotropic property of β1-AR.
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Eline A E
EA
van der Hagen
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Kukiat
K
Tudpor
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Sjoerd
S
Verkaart
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Marla
M
Lavrijsen
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Annemiete
A
van der Kemp
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Femke
F
van Zeeland
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
René J M
RJ
Bindels
From the Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands Joost.Hoenderop@radboudumc.nl.
Joost G J
JG
Hoenderop
D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007223:Infant; D051379:Mice; D008822:Mice, Transgenic; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*
D015220:Calcium Channels; D018342:Receptors, Adrenergic, beta-1; D050916:TRPV Cation Channels; C492240:Trpv5 protein, mouse; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; C517758:Prkaca protein, mouse; D002118:Calcium
Adrenergic Receptor; Calcium Channel; Phosphorylation; Protein Kinase A (PKA); Transient Receptor Potential Channels (TRP Channels)