Characterization of Small Molecule TRPC3 and TRPC6 agonist and Antagonists

Abstract

activation of the voltage sensors in the fourth transmembrane segment (S4) is transduced into pore opening via coupling of the S4-S5 linker to the C-terminal S6 segment. In TRPA1, the gain-of-function mutation N855S located in the S4-S5 region has been associated with familial episodic pain syndrome. In an attempt to elucidate the role of the S4-S5 linker and its putative interaction(s) with S6 or the first C-terminal helix in the voltage-dependent gating of TRPA1, we used site-directed mutagenesis, whole-cell electrophysiology, single-channel recording, and molecular dynamics simulations. The chargereversal mutations K868E and K969E resulted in a decrease in the rectification index compared to wild-type TRPA1 channels, and a virtually voltageindependent conductance-voltage (G-V) relationship. This effect was also observed in the adjacent charge-neutralizing mutant H970A, but was less pronounced in charge-reversal H970D. These results indicate that positively charged residues in the S4-S5 linker and the helix adjacent to the C-terminal S6 segment play a vital role in the voltage-dependent gating of TRPA1.

Mammalian TRP ion channels are insensitive to membrane stretch

“…To test whether the DAG content also modulates the chemically induced response of TRPC6, we challenged mTRPC6 transgenic worms with the TRPC6 specific agonist GSK1702934A ( Fig. 6B) (Xu et al, 2013). We found that GSK1702934A elicited dose-dependent robust withdrawal responses ( Fig.…”

Pyrazolopyrimidines as Potent Stimulators for Transient Receptor Potential Canonical 3/6/7 Channels

“…Recently, small molecular probes, including both natural products and synthetic compounds, have been reported for TRPC channels. For example, a novel synthetic agonist for TRPC3/6 named GSK1702934A ( 3 ) 25 was used at 1 μ M to study cardiac contractility and arrhythmogenesis in heart. 26 A few small-molecule compounds including Pyr3 and analogues, 27 cationic, N ′-substituted 1-benzylpiperidines, 7 anilino-thiazole, 28 norges-timate, 29 4-({(1 R ,2 R )-2-[(3 R )-3-aminopiperidin-1-yl]-2,3-dihy-dro-1 H -inden-1-yl}oxy)-3-chlorobenzonitrile, 30 and larixyl acetate 31 have been identified as inhibitors of TRPC3/6/7 channels.…”

A (+)‐Larixol Congener with High Affinity and Subtype Selectivity toward TRPC6

“…Compared to TRPC6, SH045 showedh igh selectivity over TRPA1 (630-fold),T RPV1 (400fold), TRPM2( 1400-fold) and did not have any notable effects on the other tested channels including TRPC4, 5a nd TRPV2, TRPV3,T RPM3, and TRPM8 ( Figure S2). Interestingly, SH045 is an even more potent blocker when TRPC6 is engaged via GPCR signaling (IC 50 = 8.9 nm, p < 0.05) or via TRPC6a gonist GSK1702934A [17] (IC 50 = 14.2 nm,n on-significant). This mixture leads to the formation of DAGs via G q/11 ,w hich represents the endogenous way of TRPC3/6/7 activation ( Figure 1B).…”

“…This mixture leads to the formation of DAGs via G q/11 ,w hich represents the endogenous way of TRPC3/6/7 activation ( Figure 1B). Interestingly, SH045 is an even more potent blocker when TRPC6 is engaged via GPCR signaling (IC 50 = 8.9 nm, p < 0.05) or via TRPC6a gonist GSK1702934A [17] (IC 50 = 14.2 nm,n on-significant). One could therefore speculate that SH045-inducedb lock is more potent when TRPC6 is activatedf rom the cytosolic site.…”