Harnessing Protein Unfolding for Thermosensing: Structural Insights from TRPV3

Abstract

How proteins sense temperature with high precision is a fundamental biological challenge. Here, we structurally elucidate a dynamics-based mechanism for thermoTRPs, termed suicidal gating, in which extreme thermosensitivity arises from intrinsic instability and concerted protein dynamics, coupling channel opening to partial protein unfolding. Using cryo-EM, we directly capture heat-induced partial unfolding within the channels central pore domain, a structural core of gating. Analysis of mutant structures capturing intermediate activated states reveals no large domain shifts despite high temperature dependence, only subtle interfacial changes between domains. Both mutation and heat treatment consistently impact a critical network of thermolabile "latch" interactions along the S6-TRP helix-proximal N-terminus axis, driving receptor activation from a stable closed structure to progressively decoupled states and eventual disintegration. These findings provide direct structural evidence for a new receptor mechanism and establish a broader paradigm in which distributed structural flexibility, rather than localized dedicated sensors, drives extreme biological functions.