PIRT the TRP channel regulating protein binds calmodulin and cholesterol-like ligands

Nicholas J. Sisco, Dustin D. Luu, Minjoo Kim, Wade D. Van Horn

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Transient receptor potential (TRP) ion channels are polymodal receptors that have been implicated in a variety of pathophysiologies, including pain, obesity, and cancer. The capsaicin and heat sensor TRPV1, and the menthol and cold sensor TRPM8, have been shown to be modulated by the membrane protein PIRT (Phosphoinositide-interacting regulator of TRP). The emerging mechanism of PIRT-dependent TRPM8 regulation involves a competitive interaction between PIRT and TRPM8 for the activating phosphatidylinositol 4,5-bisphosphate (PIP2) lipid. As many PIP2 modulated ion channels also interact with calmodulin, we investigated the possible interaction between PIRT and calmodulin. Using microscale thermophoresis (MST), we show that calmodulin binds to the PIRT C-terminal α-helix, which we corroborate with a pull-down experiment, nuclear magnetic resonance-detected binding study, and Rosetta-based computational studies. Furthermore, we identify a cholesterol-recognition amino acid consensus (CRAC) domain in the outer leaflet of the first transmembrane helix of PIRT, and with MST, show that PIRT specifically binds to a number of cholesterol-derivatives. Additional studies identified that PIRT binds to cholecalciferol and oxytocin, which has mechanistic implications for the role of PIRT regulation of additional ion channels. This is the first study to show that PIRT specifically binds to a variety of ligands beyond TRP channels and PIP2.

Original languageEnglish (US)
Article number478
Issue number3
StatePublished - Mar 2020


  • Calmodulin
  • Microscale thermophoresis
  • Nuclear magnetic resonance
  • PIP
  • PIRT
  • TRP channels
  • β-estradiol

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


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