J Am Soc Nephrol. 2012 Jul;23(7):1172-80. doi: 10.1681/ASN.2011100972. Epub 2012 Apr 19.

Protein kinase G inhibits flow-induced Ca2+ entry into collecting duct cells.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Du, J., Wong, W. Y., Sun, L., Huang, Y., Yao, X.,
["School of Biomedical Sciences, Chinese University of Hong Kong, China."]
The renal cortical collecting duct (CCD) contributes to the maintenance of K(+) homeostasis by modulating renal K(+) secretion. Cytosolic Ca(2+) ([Ca(2+)](i)) mediates flow-induced K(+) secretion in the CCD, but the mechanisms regulating flow-induced Ca(2+) entry into renal epithelial cells are not well understood. Here, we found that atrial natriuretic peptide, nitric oxide, and cyclic guanosine monophosphate (cGMP) act through protein kinase G (PKG) to inhibit flow-induced increases in [Ca(2+)](i) in M1-CCD cells. Coimmunoprecipitation, double immunostaining, and functional studies identified heteromeric TRPV4-P2 channels as the mediators of flow-induced Ca(2+) entry into M1-CCD cells and HEK293 cells that were coexpressed with both TRPV4 and TRPP2. In these HEK293 cells, introducing point mutations at two putative PKG phosphorylation sites on TRPP2 abolished the ability of cGMP to inhibit flow-induced Ca(2+) entry. In addition, treating M1-CCD cells with fusion peptides that compete with the endogenous PKG phosphorylation sites on TRPP2 also abolished the cGMP-mediated inhibition of the flow-induced Ca(2+) entry. Taken together, these data suggest that heteromeric TRPV4-P2 channels mediate the flow-induced entry of Ca(2+) into collecting duct cells. Furthermore, substances such as atrial natriuretic peptide and nitric oxide, which increase cGMP, abrogate flow-induced Ca(2+) entry through PKG-mediated inhibition of these channels.
PMID: 22518003External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Validation: In vivo validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Assay with endogenous proteins Assay with overexpressed proteins Reference
Cell or tissue Cell or tissue TRP channel construct Interactor construct
TRP channel Interactor Method Species Region Species Region
TRPV4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunoprecipitation HEK293 Mouse Full-length Human Full-length 22518003
TRPV4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunoprecipitation CRL-2038 (Mouse renal cortical collecting duct cell line / M1-CCD) Mouse Full-length Human Full-length 22518003
TRPV4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunofluorescence staining HEK293 Mouse Full-length Human Full-length 22518003
TRPV4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunofluorescence staining CRL-2038 (Mouse renal cortical collecting duct cell line / M1-CCD) Mouse Full-length Human Full-length 22518003
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Functional consequence Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
TRP channel Interactor Method Post-translational modification Subcellular trafficking Activity Reference
TRPV4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Calcium measurement New channel creation 22518003
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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