Pflugers Arch. 2012 Jun;463(6):779-97. doi: 10.1007/s00424-012-1098-7. Epub 2012 Mar 30.

The TRPM8 ion channel comprises direct Gq protein-activating capacity.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Klasen, K., Hollatz, D., Zielke, S., Gisselmann, G., Hatt, H., Wetzel, C. H.,
["Lehrstuhl fur Zellphysiologie, Ruhr-Universitat Bochum, Universitatsstrasse 150, 44780 Bochum, Germany."]
The transient receptor potential (TRP) family of ion channels comprises receptors that are activated by a vast variety of physical as well as chemical stimuli. TRP channels interact in a complex manner with several intracellular signaling cascades, both up- and downstream of receptor activation. Investigating cascades stimulated downstream of the cold and menthol receptor TRPM8, we found evidence for both, functional and structural interaction of TRPM8 with Galphaq. We demonstrated menthol-evoked increase in intracellular Ca(2+) under extracellular Ca(2+)-free conditions, which was blocked by the PLC inhibitors U73122 or edelfosine. This metabotropic Ca(2+) signal could be observed also in cells expressing a channel-dead (i.e. non-conducting) or a chloride-conducting TRPM8 pore mutant. However, this intracellular metabotropic Ca(2+) signal could not be detected in Galphaq deficient cells or in the presence of dominant-negative GalphaqX. Evidence for a close spatial proximity necessary for physical interaction of TRPM8 and Galphaq was provided by acceptor bleaching experiments demonstrating FRET between TRPM8-CFP and Galphaq-YFP. A Galphaq-YFP mobility assay (FRAP) revealed a restricted diffusion of Galphaq-YFP under conditions when TRPM8 is immobilized in the plasma membrane. Moreover, a menthol-induced and TRPM8-mediated G protein activation could be demonstrated by FRET experiments monitoring the dissociation of Galphaq-YFP from a Gbeta/Ggamma-CFP complex, and by the exchange of radioactive [(35)S]GTPgammaS for GDP. Our observations lead to a view that extends the operational range of the TRPM8 receptor from its function as a pure ion channel to a molecular switch with additional metabotropic capacity.
PMID: 22460725External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Screening Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Experimental screening Non-experimental screening Reference
TRP channel construct Interactor source
TRP channel Interactor Method Species Region Species Organ/tissue Sample type
TRPM8 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Gơq Inference Prediction 22460725
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
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
TRPM8 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Gơq Co-immunofluorescence staining HEK293 Not specified Full-length Not specified Full-length 22460725
TRPM8 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Gơq Fluorescence resonance energy transfer HEK293 Not specified Full-length Not specified Full-length 22460725
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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