J Biol Chem. 2014 Mar 7;289(10):6372-82. doi: 10.1074/jbc.M113.546556. Epub 2014 Jan 24.

Molecular determinants mediating gating of Transient Receptor Potential Canonical (TRPC) channels by stromal interaction molecule 1 (STIM1).External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Lee, K. P., Choi, S., Hong, J. H., Ahuja, M., Graham, S., Ma, R., So, I., Shin, D. M., Muallem, S., Yuan, J. P.,
["From the Department of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon 305-764, Republic of Korea."]
Transient receptor potential canonical (TRPC) channels mediate a critical part of the receptor-evoked Ca(2+) influx. TRPCs are gated open by the endoplasmic reticulum Ca(2+) sensor STIM1. Here we asked which stromal interaction molecule 1 (STIM1) and TRPC domains mediate the interaction between them and how this interaction is used to open the channels. We report that the STIM1 Orai1-activating region domain of STIM1 interacts with the TRPC channel coiled coil domains (CCDs) and that this interaction is essential for opening the channels by STIM1. Thus, disruption of the N-terminal (NT) CCDs by triple mutations eliminated TRPC surface localization and reduced binding of STIM1 to TRPC1 and TRPC5 while increasing binding to TRPC3 and TRPC6. Single mutations in TRPC1 NT or C-terminal (CT) CCDs reduced interaction and activation of TRPC1 by STIM1. Remarkably, single mutations in the TRPC3 NT CCD enhanced interaction and regulation by STIM1. Disruption in the TRPC3 CT CCD eliminated regulation by STIM1 and the enhanced interaction caused by NT CCD mutations. The NT CCD mutations converted TRPC3 from a TRPC1-dependent to a TRPC1-independent, STIM1-regulated channel. TRPC1 reduced the FRET between BFP-TRPC3 and TRPC3-YFP and between CFP-TRPC3-YFP upon stimulation. Accordingly, knockdown of TRPC1 made TRPC3 STIM1-independent. STIM1 dependence of TRPC3 was reconstituted by the TRPC1 CT CCD alone. Knockout of Trpc1 and Trpc3 similarly inhibited Ca(2+) influx, and inhibition of Trpc3 had no further effect on Ca(2+) influx in Trpc1(-/-) cells. Cell stimulation enhanced the formation of Trpc1-Stim1-Trpc3 complexes. These findings support a model in which the TRPC3 NT and CT CCDs interact to shield the CT CCD from interaction with STIM1. The TRPC1 CT CCD dissociates this interaction to allow the STIM1 Orai1-activating region within STIM1 access to the TRPC3 CT CCD and regulation of TRPC3 by STIM1. These studies provide evidence that the TRPC channel CCDs participate in channel gating.
PMID: 24464579External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Validation: In vivo validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  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 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation HEK293 Not specified Full-length Human Full-length 24464579
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation Not specified Full-length (mutant) Human Full-length 24464579
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation HEK293 Not specified Full-length Human Full-length 24464579
TRPC5 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation HEK293 Not specified Full-length Human Full-length 24464579
TRPC6 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation Not specified Full-length (mutant) Human Full-length 24464579
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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