J Biol Chem. 2009 Dec 25;284(52):36248-61. doi: 10.1074/jbc.M109.012872. Epub 2009 Oct 7.

Regulation of TRPC1 and TRPC4 cation channels requires an alpha1-syntrophin-dependent complex in skeletal mouse myotubes.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Sabourin, J., Lamiche, C., Vandebrouck, A., Magaud, C., Rivet, J., Cognard, C., Bourmeyster, N., Constantin, B.,
["Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Universite de Poitiers, 86022 Poitiers, France."]
The dystrophin-associated protein complex (DAPC) is essential for skeletal muscle, and the lack of dystrophin in Duchenne muscular dystrophy results in a reduction of DAPC components such as syntrophins and in fiber necrosis. By anchoring various molecules, the syntrophins may confer a role in cell signaling to the DAPC. Calcium disorders and abnormally elevated cation influx in dystrophic muscle cells have suggested that the DAPC regulates some sarcolemmal cationic channels. We demonstrated previously that mini-dystrophin and alpha1-syntrophin restore normal cation entry in dystrophin-deficient myotubes and that sarcolemmal TRPC1 channels associate with dystrophin and the bound PDZ domain of alpha1-syntrophin. This study shows that small interfering RNA (siRNA) silencing of alpha1-syntrophin dysregulated cation influx in myotubes. Moreover, deletion of the PDZ-containing domain prevented restoration of normal cation entry by alpha1-syntrophin transfection in dystrophin-deficient myotubes. TRPC1 and TRPC4 channels are expressed at the sarcolemma of muscle cells; forced expression or siRNA silencing showed that cation influx regulated by alpha1-syntrophin is supported by TRPC1 and TRPC4. A molecular association was found between TRPC1 and TRPC4 channels and the alpha1-syntrophin-dystrophin complex. TRPC1 and TRPC4 channels may form sarcolemmal channels anchored to the DAPC, and alpha1-syntrophin is necessary to maintain the normal regulation of TRPC-supported cation entry in skeletal muscle. Cation channels with DAPC form a signaling complex that modulates cation entry and may be crucial for normal calcium homeostasis in skeletal muscles.
PMID: 19812031External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Screening Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Experimental screening Non-experimental screening Reference
TRP channel construct Interactor source
TRP channel Interactor Method Species Region Species Organ/tissue Sample type
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Inference Prediction 19812031
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Validation: In vitro validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Assay with recombinant proteins Reference
TRP channel construct Interactor construct
TRP channel Interactor Method Species Region Expression system Species Region Expression system
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Fusion protein-pull down assay Not used C57BL/10 mouse muscle cell lysates Mouse 75-170 E. coli 19812031
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Fusion protein-pull down assay Not used C57BL/10 mouse muscle cell lysates Mouse 75-170 E. coli 19812031
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
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 ơ1-syntrophin Co-immunoprecipitation SolD6 19812031
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Co-immunoprecipitation C57BL/10 mouse muscle cell 19812031
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC4 Co-immunoprecipitation C57BL/10 mouse muscle cell 19812031
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Co-immunoprecipitation C57BL/10 mouse muscle cell 19812031
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC1 Co-immunoprecipitation C57BL/10 mouse muscle cell 19812031
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Characterization Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Binding region mapping Stoichiometry Affinity (Kd) Reference
TRP channel Interactor
TRP channel Interactor Method Species Region Species Region
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Fusion protein-pull down assay Mouse Not determined Mouse 75-170 19812031
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 ơ1-syntrophin Fusion protein-pull down assay Mouse Not determined Mouse 75-170 19812031
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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