Biochem J. 2001 May 1;355(Pt 3):663-70.

The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Trost, C., Bergs, C., Himmerkus, N., Flockerzi, V.,
["Institut fur Pharmakologie und Toxikologie der Universitat des Saarlandes, D-66421 Homburg, Germany. claudia.trost@med-rz.uni-sb.de"]
The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca(2+)-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca(2+)-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1) retention of in vitro translated TRP4 and of TRP4 protein solubilized from bovine adrenal cortex by CaM-Sepharose in the presence of Ca(2+), and (2) TRP4-glutathione S-transferase pull-down experiments. Two domains of TRP4, amino acid residues 688-759 and 786-848, were identified as being able to interact with CaM. The binding of CaM to both domains occurred only in the presence of Ca(2+) concentrations above 10 microM, with half maximal binding occurring at 16.6 microM (domain 1) and 27.9 microM Ca(2+) (domain 2). Synthetic peptides, encompassing the two putative CaM binding sites within these domains and covering amino acid residues 694-728 and 829-853, interacted directly with dansyl-CaM with apparent K(d) values of 94-189 nM. These results indicate that TRP4/Ca(2+)-CaM are parts of a signalling complex involved in agonist-induced Ca(2+) entry.
PMID: 11311128External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
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
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fusion protein-pull down assay Not used Bovine adrenal cortex lysates Xenopus Full-length In vitro translation 11311128
(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
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fusion protein-pull down assay Mouse 786-848 Not specified Not determined 11311128
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fusion protein-pull down assay Mouse 688-759 Not specified Not determined 11311128
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fluorescence probe labeling Mouse 694-718 Bovine Not determined 94 nM 11311128
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fluorescence probe labeling Mouse 829-853 Bovine Not determined 138 nM 11311128
TRPC4 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Calmodulin Fluorescence probe labeling Mouse 708-728 Bovine Not determined 189 nM 11311128
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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