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

Sci Rep. 2017 Sep 5;7(1):10522. doi: 10.1038/s41598-017-11274-1.

Abstract

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 A2 (PLA2) 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8,11,14-Eicosatrienoic Acid / analogs & derivatives*
  • 8,11,14-Eicosatrienoic Acid / chemistry
  • 8,11,14-Eicosatrienoic Acid / pharmacology
  • Amino Acid Substitution
  • Binding Sites
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Ion Channel Gating
  • Molecular Docking Simulation
  • Protein Binding
  • TRPV Cation Channels / chemistry*
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism

Substances

  • TRPV Cation Channels
  • TRPV4 protein, human
  • 5,6-epoxy-8,11,14-eicosatrienoic acid
  • 8,11,14-Eicosatrienoic Acid