J Biol Chem. 2006 May 12;281(19):13588-95. Epub 2006 Mar 13.
TRPC3 and TRPC4 associate to form a redox-sensitive cation channel. Evidence for expression of native TRPC3-TRPC4 heteromeric channels in endothelial cells.
Poteser, M., Graziani, A., Rosker, C., Eder, P., Derler, I., Kahr, H., Zhu, M. X., Romanin, C., Groschner, K.,
["Institute of Pharmaceutical Sciences, Pharmacology and Toxicology, Karl-Franzens-University of Graz, Universitaetsplatz 2, A-8010 Graz, Austria."]
["Institute of Pharmaceutical Sciences, Pharmacology and Toxicology, Karl-Franzens-University of Graz, Universitaetsplatz 2, A-8010 Graz, Austria."]
Canonical transient receptor potential proteins (TRPC) have been proposed to form homo- or heteromeric cation channels in a variety of tissues, including the vascular endothelium. Assembly of TRPC multimers is incompletely understood. In particular, heteromeric assembly of distantly related TRPC isoforms is still a controversial issue. Because we have previously suggested TRPC proteins as the basis of the redox-activated cation conductance of porcine aortic endothelial cells (PAECs), we set out to analyze the TRPC subunit composition of endogenous endothelial TRPC channels and report here on a redox-sensitive TRPC3-TRPC4 channel complex. The ability of TRPC3 and TRPC4 proteins to associate and to form a cation-conducting pore complex was supported by four lines of evidence as follows: 1) Co-immunoprecipitation experiments in PAECs and in HEK293 cells demonstrated the association of TRPC3 and TRPC4 in the same complex. 2) Fluorescence resonance energy transfer analysis demonstrated TRPC3-TRPC4 association, involving close proximity between the N terminus of TRPC4 and the C terminus of TRPC3 subunits. 3) Co-expression of TRPC3 and TRPC4 in HEK293 cells generated a channel that displayed distinct biophysical and regulatory properties. 4) Expression of dominant-negative TRPC4 proteins suppressed TRPC3-related channel activity in the HEK293 expression system and in native endothelial cells. Specifically, an extracellularly hemagglutinin (HA)-tagged TRPC4 mutant, which is sensitive to blockage by anti-HA-antibody, was found to transfer anti-HA sensitivity to both TRPC3-related currents in the HEK293 expression system and the redox-sensitive cation conductance of PAECs. We propose TRPC3 and TRPC4 as subunits of native endothelial cation channels that are governed by the cellular redox state.
PMID: 16537542

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Screening
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Experimental screening | Non-experimental screening | Reference | ||||||||
TRP channel construct | Interactor source | |||||||||
TRP channel | Interactor | Method | Species | Region | Species | Organ/tissue | Sample type | |||
TRPC3 |
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TRPC4 | Inference | Prediction | 16537542 | |||||
TRPC4 |
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TRPC3 | Inference | Prediction | 16537542 |
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)

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Validation: In vivo validation
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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 | ||||
TRPC3 |
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TRPC4 | Co-immunoprecipitation | HEK293 | Human | Full-length | Mouse | Full-length | 16537542 | |
TRPC3 |
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TRPC4 | Co-immunoprecipitation | Porcine primary aortic endothelial cell | 16537542 | |||||
TRPC3 |
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TRPC4 | Co-immunofluorescence staining | Porcine primary aortic endothelial cell | 16537542 | |||||
TRPC4 |
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TRPC3 | Co-immunoprecipitation | HEK293 | Mouse | Full-length | Human | Full-length | 16537542 | |
TRPC4 |
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TRPC3 | Co-immunoprecipitation | Porcine primary aortic endothelial cell | 16537542 | |||||
TRPC4 |
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TRPC3 | Co-immunofluorescence staining | Porcine primary aortic endothelial cell | 16537542 |
(
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
