J Biol Chem. 2010 Jan 1;285(1):731-40. doi: 10.1074/jbc.M109.052548. Epub 2009 Oct 28.
Differential regulation of TRPV1, TRPV3, and TRPV4 sensitivity through a conserved binding site on the ankyrin repeat domain.
Phelps, C. B., Wang, R. R., Choo, S. S., Gaudet, R.,
["Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA."]
["Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA."]
Transient receptor potential vanilloid (TRPV) channels, which include the thermosensitive TRPV1-V4, have large cytoplasmic regions flanking the transmembrane domain, including an N-terminal ankyrin repeat domain. We show that a multiligand binding site for ATP and calmodulin previously identified in the TRPV1 ankyrin repeat domain is conserved in TRPV3 and TRPV4, but not TRPV2. Accordingly, TRPV2 is insensitive to intracellular ATP, while, as previously observed with TRPV1, a sensitizing effect of ATP on TRPV4 required an intact binding site. In contrast, ATP reduced TRPV3 sensitivity and potentiation by repeated agonist stimulations. Thus, ATP and calmodulin, acting through this conserved binding site, are key players in generating the different sensitivity and adaptation profiles of TRPV1, TRPV3, and TRPV4. Our results suggest that competing interactions of ATP and calmodulin influence channel sensitivity to fluctuations in calcium concentration and perhaps even metabolic state. Different feedback mechanisms likely arose because of the different physiological stimuli or temperature thresholds of these channels.
PMID: 19864432
 Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
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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 | |||
| TRPV3 |
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Calmodulin | Inference | Prediction | 19864432 | |||||
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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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| Characterization
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|---|---|---|---|---|---|---|---|---|---|---|
| Binding region mapping | Stoichiometry | Affinity (Kd) | Reference | |||||||
| TRP channel | Interactor | |||||||||
| TRP channel | Interactor | Method | Species | Region | Species | Region | ||||
| TRPV1 |
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Calmodulin | Fusion protein-pull down assay | Human | 101-364 | Not specified | Not determined | 19864432 | ||
| TRPV3 |
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Calmodulin | Fusion protein-pull down assay | Human | 115-367 | Not specified | Not determined | 19864432 | ||
| TRPV4 |
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Calmodulin | Fusion protein-pull down assay | Chicken | 132-383 | Not specified | Not determined | 19864432 | ||
(:
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)