J Physiol. 2010 Oct 1;588(Pt 19):3671-82. doi: 10.1113/jphysiol.2010.194621. Epub 2010 Jul 26.

TRPC6 channels stimulated by angiotensin II are inhibited by TRPC1/C5 channel activity through a Ca2+- and PKC-dependent mechanism in native vascular myocytes.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Shi, J., Ju, M., Saleh, S. N., Albert, A. P., Large, W. A.,
["Division of Basic Medical Sciences, St George's, University of London, London SW17 0RE, UK."]
The present work investigated interactions between TRPC1/C5 and TRPC6 cation channel activities evoked by angiotensin II (Ang II) in native rabbit mesenteric artery vascular smooth muscle cells (VSMCs). In low intracellular Ca(2+) buffering conditions (0.1 mm BAPTA), 1 nm and 10 nm Ang II activated both 2 pS TRPC1/C5 channels and 15-45 pS TRPC6 channels in the same outside-out patches. However, increasing Ang II to 100 nm abolished TRPC6 activity but further increased TRPC1/C5 channel activity. Comparison of individual patches revealed an inverse relationship between TRPC1/C5 and TRPC6 channel activity suggesting that TRPC1/C5 inhibits TRPC6 channel activity. Inclusion of anti-TRPC1 and anti-TRPC5 antibodies, raised against intracellular epitopes, in the patch pipette solution blocked TRPC1/C5 channel currents but potentiated by about six-fold TRPC6 channel activity evoked by 1-100 nm Ang II in outside-out patches. Bath application of T1E3, an anti-TRPC1 antibody raised against an extracellular epitope, also increased Ang II-evoked TRPC6 channel activity. With high intracellular Ca(2+) buffering conditions (10 mm BAPTA), 10 nm Ang II-induced TRPC6 channel activity was increased by about five-fold compared to channel activity with low Ca(2+) buffering. In addition, increasing intracellular Ca(2+) levels ([Ca(2+)](i)) at the cytosolic surface inhibited 10 nm Ang II-evoked TRPC6 channel activity in inside-out patches. Moreover, in zero external Ca(2+) (0 [Ca(2+)](o)) 100 nm Ang II induced TRPC6 channel activity in outside-out patches. Pre-treatment with the PKC inhibitor, chelerythrine, markedly increased TRPC6 channel activity evoked by 1-100 nm Ang II and blocked the inhibitory action of [Ca(2+)](i) on TRPC6 channel activity. Co-immunoprecipitation studies shows that Ang II increased phosphorylation of TRPC6 proteins which was inhibited by chelerythrine, 0 [Ca(2+)](o) and the anti-TRPC1 antibody T1E3. These results show that TRPC6 channels evoked by Ang II are inhibited by TRPC1/C5-mediated Ca(2+) influx and stimulation of PKC, which phosphorylates TRPC6 subunits. These conclusions represent a novel interaction between two distinct vasoconstrictor-activated TRPC channels expressed in the same native VSMCs.
PMID: 20660561External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Functional consequence Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
TRP channel Interactor Method Post-translational modification Subcellular trafficking Activity Reference
TRPC6 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC1 Patch clamp Inhibition 20660561
TRPC6 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC5 Patch clamp Inhibition 20660561
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

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