EMBO J. 2003 Sep 15;22(18):4677-88.
Amplification of receptor signalling by Ca2+ entry-mediated translocation and activation of PLCgamma2 in B lymphocytes.
Nishida, M., Sugimoto, K., Hara, Y., Mori, E., Morii, T., Kurosaki, T., Mori, Y.,
["Division of Molecular and Cellular Physiology, Center for Integrative Bioscience, Okazaki National Research Institutes, Okazaki, Aichi 444-8585, Japan."]
["Division of Molecular and Cellular Physiology, Center for Integrative Bioscience, Okazaki National Research Institutes, Okazaki, Aichi 444-8585, Japan."]
In non-excitable cells, receptor-activated Ca2+ signalling comprises initial transient responses followed by a Ca2+ entry-dependent sustained and/or oscillatory phase. Here, we describe the molecular mechanism underlying the second phase linked to signal amplification. An in vivo inositol 1,4,5-trisphosphate (IP3) sensor revealed that in B lymphocytes, receptor-activated and store-operated Ca2+ entry greatly enhanced IP3 production, which terminated in phospholipase Cgamma2 (PLCgamma2)-deficient cells. Association between receptor-activated TRPC3 Ca2+ channels and PLCgamma2, which cooperate in potentiating Ca2+ responses, was demonstrated by co-immunoprecipitation. PLCgamma2-deficient cells displayed diminished Ca2+ entry-induced Ca2+ responses. However, this defect was canceled by suppressing IP3-induced Ca2+ release, implying that IP3 and IP3 receptors mediate the second Ca2+ phase. Furthermore, confocal visualization of PLCgamma2 mutants demonstrated that Ca2+ entry evoked a C2 domain-mediated PLCgamma2 translocation towards the plasma membrane in a lipase-independent manner to activate PLCgamma2. Strikingly, Ca2+ entry-activated PLCgamma2 maintained Ca2+ oscillation and extracellular signal-regulated kinase activation downstream of protein kinase C. We suggest that coupling of Ca2+ entry with PLCgamma2 translocation and activation controls the amplification and co-ordination of receptor signalling.
PMID: 12970180

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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 | |||
TRPC3 |
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PLCƣ2 | Inference | Prediction | 12970180 |
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)

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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 | ||||
TRPC3 |
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PLCƣ2 | Co-immunoprecipitation | HEK293 | Mouse | Full-length | Chicken | Full-length | 12970180 |
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)

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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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PLCƣ2 | Co-immunoprecipitation | Mouse | Not determined | Chicken | 810-829 | 12970180 |
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)

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Functional consequence
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TRP channel | Interactor | Method | Post-translational modification | Subcellular trafficking | Activity | Reference | ||||||
TRPC3 |
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PLCƣ2 | Calcium measurement | Activation | 12970180 | |||||||
TRPC3 |
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PLCƣ2 | Patch clamp | Activation | 12970180 |
(
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click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
