Cell Signal. 2012 Nov;24(11):2070-5. doi: 10.1016/j.cellsig.2012.06.015. Epub 2012 Jul 1.
Identification of Ser/Thr phosphorylation sites in the C2-domain of phospholipase C gamma2 (PLCgamma2) using TRPM7-kinase.
Deason-Towne, F., Perraud, A. L., Schmitz, C.,
["Department of Immunology, University of Colorado Denver, National Jewish Health, Denver, CO 80206, USA."]
["Department of Immunology, University of Colorado Denver, National Jewish Health, Denver, CO 80206, USA."]
PLC-isozymes are central elements of cellular signaling downstream of numerous receptors. PLCgamma2 is a pivotal component of B cell receptor (BCR) signaling. The regulation of PLCgamma2-dependent signaling functions by Tyr-phosphorylation is well characterized, however, the potential role of Ser/Thr phosphorylation events remains undefined. TRPM7 is the fusion of a Ser/Thr kinase with an ion channel, and an essential component of Mg(2+)-homeostasis regulation. Although the interaction between the C2 domain of several PLC-isozymes and TRPM7 is well established, previous studies have focused on the effect of PLC-activity on TRPM7. Here, we investigated whether Ser/Thr phosphorylation sites in the C2 domain of PLCgamma2 could be identified using TRPM7-kinase. We show that TRPM7-kinase phosphorylates PLCgamma2 in its C2-domain at position Ser1164 and in the linker region preceding the C2-domain at position Thr1045. Using a complementation approach in PLCgamma2(-/-) DT40 cells, we found that the PLCgamma2-S1164A mutant fully restores BCR mediated Ca(2+)-responses under standard growth conditions. However, under hypomagnesic conditions, PLCgamma2-S1164A fails to reach Ca(2+)-levels seen in cells expressing PLCgamma2 wildtype. These results suggest that Mg(2+)-sensitivity of the BCR signaling pathway may be regulated by Ser/Thr phosphorylation of PLCgamma2.
PMID: 22759789
 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 | |||
| TRPM7 |
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PLCƣ2 | Inference | Prediction | 22759789 | |||||
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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 | ||||
| TRPM7 |
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PLCƣ2 | Co-immunoprecipitation | DT40 | Mouse | Full-length | Not used | 22759789 | ||
(:
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)