Circ Res. 2008 Oct 10;103(8):e97-104. doi: 10.1161/CIRCRESAHA.108.182931. Epub 2008 Sep 18.

Interactions, functions, and independence of plasma membrane STIM1 and TRPC1 in vascular smooth muscle cells.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Li, J., Sukumar, P., Milligan, C. J., Kumar, B., Ma, Z. Y., Munsch, C. M., Jiang, L. H., Porter, K. E., Beech, D. J.,
["Multidisciplinary Cardiovascular Research Centre, Faculty of Biological Sciences, University of Leeds, United Kingdom."]
Stromal interaction molecule 1 (STIM1) is a predicted single membrane-spanning protein involved in store-operated calcium entry and interacting with ion channels including TRPC1. Here, we focus on endogenous STIM1 of modulated vascular smooth muscle cells, which exhibited a nonselective cationic current in response to store depletion despite strong buffering of intracellular calcium at the physiological concentration. STIM1 mRNA and protein were detected and suppressed by specific short interfering RNA. Calcium entry evoked by store depletion was partially inhibited by STIM1 short interfering RNA, whereas calcium release was unaffected. STIM1 short interfering RNA suppressed cell migration but not proliferation. Antibody that specifically bound STIM1 revealed constitutive extracellular N terminus of STIM1 and extracellular application of the antibody caused fast inhibition of the current evoked by store depletion. The antibody also inhibited calcium entry and cell migration but not proliferation. STIM1 interacted with TRPC1, and TRPC1 contributed partially to calcium entry and cationic current. However, the underlying processes could not be explained only by a STIM1-TRPC1 partnership because extracellular TRPC1 antibody suppressed cationic current only in a fraction of cells, TRPC1-containing channels were important for cell proliferation as well as migration, and cell surface localization studies revealed TRPC1 alone, as well as with STIM1. The data suggest a complex situation in which there is not only plasma membrane-spanning STIM1 that is important for cell migration and TRPC1-independent store-operated cationic current but also TRPC1-STIM1 interaction, a TRPC1-dependent component of store-operated current, and STIM1-independent TRPC1 linked to cell proliferation.
PMID: 18802022External 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 Human saphenous vein vascular smooth muscle cell 18802022
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunoprecipitation Human saphenous vein vascular smooth muscle cell Human Full-length Not specified Full-length 18802022
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 STIM1 Co-immunofluorescence staining Human saphenous vein vascular smooth muscle cell 18802022
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

To prevent spam comments, we use reCAPTCHA. Please type correct words into the following box.