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Updated: Jul 5, 2025

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Bidirectional Allosteric Coupling between PIP2 Binding and the Pore of the Oncochannel TRPV6

Christina Humer1, Tamara Radiskovic1, Kata Horváti2

  • 1Institute of Biophysics, Johannes Kepler University Linz, 4020 Linz, Austria.

International Journal of Molecular Sciences
|January 11, 2024
PubMed

Insights

Researchers explored how the epithelial ion channel TRPV6, crucial for calcium homeostasis, is regulated by the lipid phosphatidylinositol-4,5-bisphosphate (PIP2) and the inhibitor cis-22a. They found bidirectional allosteric communication between the PIP2 binding site and the channel pore.

Area of Science:

  • Molecular Biology
  • Biophysics
  • Physiology

Background:

  • The epithelial ion channel TRPV6 is essential for calcium homeostasis.
  • Dysregulation of TRPV6 is linked to diseases, notably cancer, highlighting the need for targeted therapies.
  • Phosphatidylinositol-4,5-bisphosphate (PIP2) is a key regulator of TRPV6 channel function.

Purpose of the Study:

  • To investigate the regulatory roles of PIP2 and the inhibitor cis-22a on TRPV6.
  • To identify specific residues involved in the interaction between cis-22a, PIP2, and TRPV6.
  • To elucidate the allosteric communication pathways between the lipid binding site and the channel pore.

Main Methods:

  • Calcium imaging
  • Electrophysiology
  • Optogenetics
  • Site-directed mutagenesis

Main Results:

  • Identified key residues in the TRPV6 pore and lipid binding site critical for regulation by cis-22a and PIP2.
  • Demonstrated bidirectional allosteric regulation between the lipid binding site and the pore.
  • Showed that mutations at the cytosolic pore exit differentially affect inhibition by cis-22a and PIP2.

Conclusions:

  • TRPV6 function is bidirectionally regulated by PIP2 and cis-22a through allosteric mechanisms.
  • Specific residues mediate the interplay between lipid binding and channel pore activity.
  • Understanding these interactions may facilitate the development of novel TRPV6-targeting drugs.
Keywords:
PIP2TRPV6calciumcis-22ainhibitionlipid

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