EMBO Rep. 2008 Jul;9(7):690-7. doi: 10.1038/embor.2008.89. Epub 2008 Jun 6.
Off-response property of an acid-activated cation channel complex PKD1L3-PKD2L1.
Inada, H., Kawabata, F., Ishimaru, Y., Fushiki, T., Matsunami, H., Tominaga, M.,
["Section of Cell Signaling, Okazaki Institute for Integrative Bioscience, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan. hinada@nips.ac.jp"]
["Section of Cell Signaling, Okazaki Institute for Integrative Bioscience, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan. hinada@nips.ac.jp"]
Ligand-gated ion channels are important in sensory and synaptic transduction. The PKD1L3-PKD2L1 channel complex is a sour taste receptor candidate that is activated by acids. Here, we report that the proton-activated PKD1L3-PKD2L1 ion channels have the unique ability to be activated after the removal of an acid stimulus. We refer to this property as the off-response (previously described as a delayed response). Electrophysiological analyses show that acid-induced responses are observed only after the removal of an acid solution at less than pH 3.0. A small increase in pH is sufficient for PKD1L3-PKD2L1 channel activation, after exposure to an acid at pH 2.5. These results indicate that this channel is a new type of ion channel-designated as an 'off-channel'-which is activated during stimulus application but not gated open until the removal of the stimulus. The off-response property of PKD1L3-PKD2L1 channels might explain the physiological phenomena occurring during sour taste sensation.
PMID: 18535624
 Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
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Validation: In vivo validation
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| Assay with endogenous proteins | Assay with overexpressed proteins | Reference | ||||||||
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| TRP channel | Interactor | Method | Species | Region | Species | Region | ||||
| TRPP2 |
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PKD1L3/Polycystin-1L3 | Co-immunoprecipitation | HEK293T | Mouse | Full-length | Mouse | Full-length | 18535624 | |
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
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Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
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top
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| Functional consequence
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| TRP channel | Interactor | Method | Post-translational modification | Subcellular trafficking | Activity | Reference | ||||||
| TRPP2 |
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PKD1L3/Polycystin-1L3 | Patch clamp | New channel creation | 18535624 | |||||||
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)