Integrative binding sites within intracellular termini of TRPV1 receptor

PLoS One. 2012;7(10):e48437. doi: 10.1371/journal.pone.0048437. Epub 2012 Oct 31.

Abstract

TRPV1 is a nonselective cation channel that integrates wide range of painful stimuli. It has been shown that its activity could be modulated by intracellular ligands PIP2 or calmodulin (CaM). The detailed localization and description of PIP2 interaction sites remain unclear. Here, we used synthesized peptides and purified fusion proteins of intracellular regions of TRPV1 expressed in E.coli in combination with fluorescence anisotropy and surface plasmon resonance measurements to characterize the PIP2 binding to TRPV1. We characterized one PIP2 binding site in TRPV1 N-terminal region, residues F189-V221, and two independent PIP2 binding sites in C-terminus: residues K688-K718 and L777-S820. Moreover we show that two regions, namely F189-V221 and L777-S820, overlap with previously localized CaM binding sites. For all the interactions the equilibrium dissociation constants were estimated. As the structural data regarding C-terminus of TRPV1 are lacking, restraint-based molecular modeling combined with ligand docking was performed providing us with structural insight to the TRPV1/PIP2 binding. Our experimental results are in excellent agreement with our in silico predictions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ankyrins / chemistry
  • Binding Sites
  • Calmodulin / chemistry
  • Calmodulin / metabolism
  • Ligands
  • Liposomes / metabolism
  • Molecular Docking Simulation
  • Mutation
  • Phosphatidylinositol Phosphates / metabolism
  • Protein Binding
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Rats
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • TRPV Cation Channels / chemistry*
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*

Substances

  • Ankyrins
  • Calmodulin
  • Ligands
  • Liposomes
  • Phosphatidylinositol Phosphates
  • Recombinant Fusion Proteins
  • TRPV Cation Channels
  • TRPV1 receptor

Associated data

  • PDB/1FIT
  • PDB/3SPI

Grant support

This project was supported by grants GACR P205/10/P308, GACR 301/10/1159 and GACR P304/12G069(http://www.gacr.cz/), RVO:67985823, RVO 61388971. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.