Picomolar, selective, and subtype-specific small-molecule inhibition of TRPC1/4/5 channels.
The concentration of free cytosolic Ca2+and the voltage across the plasma membrane are major determinants of cell function. Ca2+-permeable non-selective cationic channels are known to regulate these parameters, but understanding of these channels remains inadequate. Here we focus on transient receptor potential canonical 4 and 5 proteins (TRPC4 and TRPC5), which assemble as homomers or heteromerize with TRPC1 to form Ca2+-permeable non-selective cationic channels in many mammalian cell types. Multiple roles have been suggested, including in epilepsy, innate fear, pain, and cardiac remodeling, but limitations in tools to probe these channels have restricted progress. A key question is whether we can overcome these limitations and develop tools that are high-quality, reliable, easy to use, and readily accessible for all investigators. Here, through chemical synthesis and studies of native and overexpressed channels by Ca2+and patch-clamp assays, we describe compound 31, a remarkable small-molecule inhibitor of TRPC1/4/5 channels. Its potency ranged from 9 to 1300 pm, depending on the TRPC1/4/5 subtype and activation mechanism. Other channel types investigated were unaffected, including TRPC3, TRPC6, TRPV1, TRPV4, TRPA1, TRPM2, TRPM8, and store-operated Ca2+entry mediated by Orai1. These findings suggest identification of an important experimental tool compound, which has much higher potency for inhibiting TRPC1/4/5 channels than previously reported agents, impressive specificity, and graded subtype selectivity within the TRPC1/4/5 channel family. The compound should greatly facilitate future studies of these ion channels. We suggest naming this TRPC1/4/5-inhibitory compound Pico145.
Schools of Medicine.
Hussein N
HN
Rubaiy
Schools of Medicine.
Melanie J
MJ
Ludlow
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
Matthias
M
Henrot
Schools of Medicine.
Hannah J
HJ
Gaunt
Schools of Medicine.
Katarina
K
Miteva
Schools of Medicine.
Sin Ying
SY
Cheung
Schools of Medicine; Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan.
Yasuyuki
Y
Tanahashi
Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
Nurasyikin
N
Hamzah
Schools of Medicine.
Katie E
KE
Musialowski
Schools of Medicine.
Nicola M
NM
Blythe
Schools of Medicine.
Hollie L
HL
Appleby
Schools of Medicine.
Marc A
MA
Bailey
Schools of Medicine.
Lynn
L
McKeown
Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
Roger
R
Taylor
Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom.
Richard
R
Foster
Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
Herbert
H
Waldmann
Lead Discovery Center GmbH, Otto-Hahn-Strasse 15, D-44227 Dortmund, Germany.
Peter
P
Nussbaumer
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
Mathias
M
Christmann
Schools of Medicine.
Robin S
RS
Bon
School of Pharmacy, Aichi-Gakuin University, 1-100 Kusumoto, Chikusa, Nagoya 464-8650, Japan. Electronic address: kmuraki@dpc.aichi-gakuin.ac.jp.
Katsuhiko
K
Muraki
Schools of Medicine. Electronic address: d.j.beech@leeds.ac.uk.
David J
DJ
Beech
D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000737:chemistry* / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D000071740:ORAI1 Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D050052:TRPC Cation Channels / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
D002121:Calcium Channel Blockers; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; D050052:TRPC Cation Channels; C489571:TRPC4 ion channel; C491780:TRPC5 protein, human; C096351:transient receptor potential cation channel, subfamily C, member 1; D002118:Calcium
calcium; calcium release-activated calcium channel protein 1 (ORAI1); englerin; heteromeric channel; ion channel; non-selective cationic channel; pharmacology; store-operated calcium entry; transient receptor potential canonical; transient receptor potential channels (TRP channels)