Proc Natl Acad Sci U S A. 2007 Apr 10;104(15):6454-9. Epub 2007 Apr 2.
Regulation of ryanodine receptor-dependent calcium signaling by polycystin-2.
Anyatonwu, G. I., Estrada, M., Tian, X., Somlo, S., Ehrlich, B. E.,
["Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA."]
["Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA."]
Mutations in polycystin-2 (PC2) cause autosomal dominant polycystic kidney disease. A function for PC2 in the heart has not been described. Here, we show that PC2 coimmunoprecipitates with the cardiac ryanodine receptor (RyR2) from mouse heart. Biochemical assays showed that the N terminus of PC2 binds the RyR2, whereas the C terminus only binds to RyR2 in its open state. Lipid bilayer electrophysiological experiments indicated that the C terminus of PC2 functionally inhibited RyR2 channel activity in the presence of calcium (Ca(2+)). Pkd2(-/-) cardiomyocytes had a higher frequency of spontaneous Ca(2+) oscillations, reduced Ca(2+) release from the sarcoplasmic reticulum stores, and reduced Ca(2+) content compared with Pkd2(+/+) cardiomyocytes. In the presence of caffeine, Pkd2(-/-) cardiomyocytes exhibited decreased peak fluorescence, a slower rate of rise, and a longer duration of Ca(2+) transients compared with Pkd2(+/+). These data suggest that PC2 is important for regulation of RyR2 function and that loss of this regulation of RyR2, as occurs when PC2 is mutated, results in altered Ca(2+) signaling in the heart.
PMID: 17404231
 Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
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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 | |||
| TRPP1 |
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RyR2 | Inference | Prediction | 17404231 | |||||
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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 | ||
| TRPP1 |
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RyR2 | Fusion protein-pull down assay | Human | 1-703 | MDCK lysates | Not used | Mouse cardiac tissue microsome | 17404231 | |
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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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| 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 | ||||
| TRPP1 |
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RyR2 | Co-immunoprecipitation | Mouse heart tissue | 17404231 | |||||
(:
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 | ||||
| TRPP1 |
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RyR2 | Fusion protein-pull down assay | Human | 703-968 | Mouse | Not determined | 17404231 | ||
| TRPP1 |
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RyR2 | Fusion protein-pull down assay | Human | 130-220 | Mouse | Not determined | 17404231 | ||
(:
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:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)