FASEB J. 2014 Jan;28(1):244-55. doi: 10.1096/fj.13-238022. Epub 2013 Sep 10.
Myristoylated alanine-rich C kinase substrate coordinates native TRPC1 channel activation by phosphatidylinositol 4,5-bisphosphate and protein kinase C in vascular smooth muscle.
Shi, J., Birnbaumer, L., Large, W. A., Albert, A. P.,
["1Pharmacology and Cell Physiology, Division of Biomedical Sciences, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK. aalbert@sgul.ac.uk."]
["1Pharmacology and Cell Physiology, Division of Biomedical Sciences, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK. aalbert@sgul.ac.uk."]
Canonical transient receptor potential 1 (TRPC1) Ca(2+)-permeable cation channels contribute to vascular tone and blood vessel remodeling and represent potential therapeutic targets for cardiovascular disease. Protein kinase C (PKC) and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] are obligatory for native TRPC1 channel activation in vascular smooth muscle cells (VSMCs) but how PKC and PI(4,5)P2 act together to induce channel gating remains unresolved. The present study reveals that myristoylated alanine-rich C kinase substrate (MARCKS) protein coordinates activation of TRPC1 channels by PKC and PI(4,5)P2. TRPC1 channels and MARCKS form signaling complexes with PI(4,5)P2 bound to MARCKS; in this configuration TRPC1 channels are closed. Activators of TRPC1 channels induce PKC phosphorylation of TRPC1 proteins, which causes dissociation of TRPC1 subunits from MARCKS and release of PI(4,5)P2 from MARCKS; PI(4,5)P2 subsequently binds to TRPC1 subunits to induce channel opening. Calmodulin acting at, or upstream of, MARCKS is also required for TRPC1 channel opening through a similar gating mechanism involving PKC and PI(4,5)P2. These novel findings show that MARCKS coordinates native TRPC1 channel activation in VSMCs by acting as a reversible PI(4,5)P2 buffer, which is regulated by PKC-mediated TRPC1 phosphorylation. Moreover, our data provide evidence that PI(4,5)P2 is a gating ligand of TRPC1 channels.
PMID: 24022404
 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 | |||
| TRPC1 |
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MARCKS | Inference | Prediction | 24022404 | |||||
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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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| 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 | ||||
| TRPC1 |
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MARCKS | Co-immunoprecipitation | Rabbit portal vein tissue lysates | 24022404 | |||||
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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)
|
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 | ||||||
| TRPC1 |
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MARCKS | Patch clamp | Inhibition | 24022404 | |||||||
(:
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)