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Discrete control of TRPV4 channel function in the distal nephron by protein kinases A and C.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2013 Jul 12; Vol. 288 (28), pp. 20306-14. Date of Electronic Publication: 2013 May 24. - Publication Year :
- 2013
-
Abstract
- We have recently documented that the Ca(2+)-permeable TRPV4 channel, which is abundantly expressed in distal nephron cells, mediates cellular Ca(2+) responses to elevated luminal flow. In this study, we combined Fura-2-based [Ca(2+)]i imaging with immunofluorescence microscopy in isolated split-opened distal nephrons of C57BL/6 mice to probe the molecular determinants of TRPV4 activity and subcellular distribution. We found that activation of the PKC pathway with phorbol 12-myristate 13-acetate significantly increased [Ca(2+)]i responses to flow without affecting the subcellular distribution of TRPV4. Inhibition of PKC with bisindolylmaleimide I diminished cellular responses to elevated flow. In contrast, activation of the PKA pathway with forskolin did not affect TRPV4-mediated [Ca(2+)]i responses to flow but markedly shifted the subcellular distribution of the channel toward the apical membrane. These actions were blocked with the specific PKA inhibitor H-89. Concomitant activation of the PKA and PKC cascades additively enhanced the amplitude of flow-induced [Ca(2+)]i responses and greatly increased basal [Ca(2+)]i levels, indicating constitutive TRPV4 activation. This effect was precluded by the selective TRPV4 antagonist HC-067047. Therefore, the functional status of the TRPV4 channel in the distal nephron is regulated by two distinct signaling pathways. Although the PKA-dependent cascade promotes TRPV4 trafficking and translocation to the apical membrane, the PKC-dependent pathway increases the activity of the channel on the plasma membrane.
- Subjects :
- Animals
Calcium metabolism
Colforsin pharmacology
Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors
Enzyme Activation drug effects
Fura-2 chemistry
Fura-2 metabolism
In Vitro Techniques
Indoles pharmacology
Isoquinolines pharmacology
Kidney Tubules, Collecting metabolism
Maleimides pharmacology
Mice
Mice, Inbred C57BL
Microscopy, Fluorescence
Morpholines pharmacology
Nephrons drug effects
Perfusion methods
Phorbol Esters pharmacology
Protein Kinase C antagonists & inhibitors
Protein Kinase Inhibitors pharmacology
Protein Transport drug effects
Pyrroles pharmacology
Signal Transduction drug effects
Sulfonamides pharmacology
TRPV Cation Channels antagonists & inhibitors
Cyclic AMP-Dependent Protein Kinases metabolism
Nephrons metabolism
Protein Kinase C metabolism
TRPV Cation Channels metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 288
- Issue :
- 28
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 23709216
- Full Text :
- https://doi.org/10.1074/jbc.M113.466797