Mol Cell Biochem. 2009 Aug;328(1-2):25-32. doi: 10.1007/s11010-009-0070-0. Epub 2009 Mar 10.
Glutamate at position 227 of junctophilin-2 is involved in binding to TRPC3.
Woo, J. S., Hwang, J. H., Ko, J. K., Kim do, H., Ma, J., Lee, E. H.,
["Department of Physiology, The Catholic University of Korea, Seoul, Korea."]
["Department of Physiology, The Catholic University of Korea, Seoul, Korea."]
Canonical-type transient receptor potential cation channel type 3 (TRPC3) allows the entry of extracellular Ca(2+) and Na(+) into various cells. In mouse skeletal myotubes, functional interaction between TRPC3 and RyR1 (ryanodine receptor type 1/Ca(2+)-release channel on sarcoplasmic reticulum membrane) regulates the gain of excitation-contraction coupling. Junctophilin-2 (JP2) is a TRPC3-interacting protein in mouse skeletal myotubes. Based on these knowledge from bona-fide TRPC3-expressing cells, to identify critical binding region(s) of JP2 that participate in binding to TRPC3, various JP2 portions were subjected to co-immunoprecipitation assay with intact TRPC3 from rabbit skeletal muscle. A region covering 143 to 234 amino acids of JP2 (F1-2) was the most efficient portion binding to TRPC3. Through mutational studies, we found that the binding ability of JP2 to TRPC3 was mainly due to glutamate in the F1-2 region (E227). This substantial binding between JP2 and TRPC3 suggests that JP2 can be a regulatory protein of TRPC3 and/or TRPC3-mediated Ca(2+) homeostasis in skeletal muscle.
PMID: 19277847
 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 | ||
| TRPC3 |
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Junctophilin-2 | Fusion protein-pull down assay | Not used | Rabbit back and leg fast-twich skeletal muscle lysates | Mouse | Full-length | E. coli | 19277847 | |
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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 | ||||
| TRPC3 |
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Junctophilin-2 | Fusion protein-pull down assay | Mouse | Not determined | Mouse | 143-234 | 19277847 | ||
(:
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)