Year: 2025
Type: article
Abstract: Single-channel electrophysiology probes ion channel gating, but how can one probe membrane transport when the single-unit current is undetectable? We pulled membrane tethers from live cells to isolate individual transmembrane proteins. The tether constrained diffusion of transported substrate to the tether axis, leading to ∼1000-fold enhancement of substrate concentration and observation time compared to planar membranes. Fluorescent reporters inside the tether revealed individual transport events. We imaged unitary Ca 2+ transport events in tethers containing the low-conductance T-type Ca 2+ channel Ca V 3.2, and compared our results to ensemble electrophysiology and stochastic gating simulations. This work establishes tether-based single-channel recordings as a powerful tool to study dynamics of membrane transport. TOC Graphic
Source: ACS Nano
Authors: Madeleine R. Howell, Adam E. Cohen
Institution: Harvard University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W4412420022