Biophysical Society Conference | Tahoe 2022

Molecular Biophysics of Membranes

Poster Abstracts

47-POS Board 12 DECONSTRUCTING THE POLYMODAL FUNCTION OF THE TRPV1 HEAT- SENSOR FROM BIOPHYSICAL STUDIES Wade D. Van Horn ; Dustin D Luu 1 ; Mubark D Mebrat 1 ; Aerial M Owens 1 ; Karan H Shah 1 ; Yu- Tzu Chang 1 ; 1 Arizona State University, School of Molecular Sciences, Tempe, AZ, USA The ability to sense temperature is crucial. The TRPV1 ion channel is the canonical heat sensor in eukaryotes, where it acts as a molecular thermometer. Beyond temperature-sensing, TRPV1 is also activated by protons (low pH), and chemical ligands, like capsaicin the pungent compound from chili peppers. Heat, protons, and ligands gate TRPV1. This polymodal regulation by diverse stimuli provides a platform to probe fundamental aspects in membrane proteins, including transmembrane allostery and cooperativity. Building on variable temperature NMR and whole-cell patch-clamp electrophysiology experiments, we have identified the minimal domains and regions required to detect heat, ligands, and protons. Our biophysical results indicate that temperature-sensing is isolated to the transmembrane domain and for the first time quantifies contributions from distinct regions. Additionally, our studies identify allosteric networks that form the molecular basis for cross-talk between activation mechanisms, including that these allosteric networks remain intact in isolated transmembrane domains. In an effort to validate these outcomes, we’ve adapted a recently developed method where recombinantly expressed and purified membrane proteins can be delivered to mammalian cells for functional characterization. Patch-clamp electrophysiology characterization of a bacterially purified biophysical construct validates that a minimal TRPV1 domain is sufficient to recapitulate polymodal functional behavior that was identified from NMR and other biophysical studies.

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