Structural determinants of 5′,6′-epoxyeicosatrienoic acid binding to and activation of TRPV4 channel

• Published in: Scientific reports Vol. 7; no. 1; p. 10522
• Main Authors: Berna-Erro, Alejandro, Izquierdo-Serra, Mercè, Sepúlveda, Romina V., Rubio-Moscardo, Fanny, Doñate-Macián, Pau, Serra, Selma A., Carrillo-Garcia, Julia, Perálvarez-Marín, Alex, González-Nilo, Fernando, Fernández-Fernández, José M., Valverde, Miguel A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05-09-2017; Nature Publishing Group
• Subjects: 119/118; 14; 14/34; 42/109; 631/443/1338/1872; 631/80/86/2372; 8,11,14-Eicosatrienoic Acid - analogs & derivatives; 8,11,14-Eicosatrienoic Acid - chemistry; 8,11,14-Eicosatrienoic Acid - pharmacology; 9/74; Amino Acid Substitution; Arachidonic acid; Binding Sites; Cell size; Channel gating; Cytochrome P450; Endothelium; HEK293 Cells; HeLa Cells; Humanities and Social Sciences; Humans; Ion Channel Gating; Ion channel signalling; Ligands; Molecular Docking Simulation; multidisciplinary; Phospholipase A2; Physiology; Protein Binding; Science; Science (multidisciplinary); Simulation; TRPV Cation Channels - chemistry; TRPV Cation Channels - genetics; TRPV Cation Channels - metabolism; Vasodilation
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-11274-1

TRPV4 cation channel activation by cytochrome P450-mediated derivatives of arachidonic acid (AA), epoxyeicosatrienoic acids (EETs), constitute a major mechanisms of endothelium-derived vasodilatation. Besides, TRPV4 mechano/osmosensitivity depends on phospholipase A
2
(PLA
2
) activation and subsequent production of AA and EETs. However, the lack of evidence for a direct interaction of EETs with TRPV4 together with claims of EET-independent mechanical activation of TRPV4 has cast doubts on the validity of this mechanism. We now report: 1) The identification of an EET-binding pocket that specifically mediates TRPV4 activation by 5′,6′-EET, AA and hypotonic cell swelling, thereby suggesting that all these stimuli shared a common structural target within the TRPV4 channel; and 2) A structural insight into the gating of TRPV4 by a natural agonist (5′,6′-EET) in which K535 plays a crucial role, as mutant TRPV4-K535A losses binding of and gating by EET, without affecting GSK1016790A, 4α-phorbol 12,13-didecanoate and heat mediated channel activation. Together, our data demonstrates that the mechano- and osmotransducing messenger EET gates TRPV4 by a direct action on a site formed by residues from the S2-S3 linker, S4 and S4-S5 linker.