Cell Calcium. 2002 Oct;32(4):201-7.
Ca(2+)-calmodulin regulates receptor-operated Ca(2+) entry activity of TRPC6 in HEK-293 cells.
Boulay, G.,
["Department of Pharmacology, Universite de Sherbrooke, Que, J1H 5N4, Sherbrooke, Canada. Guylain.Boulay@USherbrooke.ca"]
["Department of Pharmacology, Universite de Sherbrooke, Que, J1H 5N4, Sherbrooke, Canada. Guylain.Boulay@USherbrooke.ca"]
Mammalian homologues of the Drosophila transient receptor potential channel (TRPC) are involved in Ca(2+) entry following agonist stimulation of nonexcitable cells. Seven mammalian TRPCs have been cloned but their mechanisms of activation and/or regulation are still the subject of intense research efforts. It has already been shown that calmodulin (CaM) can regulate the activity of Drosophila TRP and TRPL and, more recently, CaM has been shown to interact with mammalian TRPCs. In this study, TRPC6 stably transfected into HEK-293 cells was used to investigate the possible influence of CaM on TRPC6-dependent Ca(2+) entry. Overexpression of TRPC6 in mammalian cells is known to enhance agonist-induced Ca(2+) entry, but not thapsigargin-induced Ca(2+) entry. Here, we show that CaM inhibitors (calmidazolium and trifluoperazine) abolish receptor-operated Ca(2+) entry (ROCE) without affecting thapsigargin-operated Ca(2+) entry and that the activity of CaM is dependent on complexation with Ca(2+). We also show that Ca(2+)-CaM binds to TRPC6 and that the binding can be abolished by CaM inhibitors. These results indicate that CaM is involved in the modulation of ROCE.
PMID: 12379180
 Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
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Validation: In vitro validation
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| Assay with recombinant proteins | Reference | |||||||||
| TRP channel construct | Interactor construct | |||||||||
| TRP channel | Interactor | Method | Species | Region | Expression system | Species | Region | Expression system | ||
| TRPC6 |
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Calmodulin | Fusion protein-pull down assay | Mouse | 828-883 | E. coli | Not specified | Full-length | In vitro translation | 12379180 |
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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 | ||||||
| TRPC6 |
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Calmodulin | Calcium measurement | Activation | 12379180 | |||||||
| TRPC6 |
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Calmodulin | Patch clamp | Activation | 12379180 | |||||||
(:
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)