Activity and Ca2+ regulate the mobility of TRPV1 channels in the plasma membrane of sensory neurons

Abstract
Article and author information
Metrics

Abstract

TRPV1 channels are gated by a variety of thermal, chemical, and mechanical stimuli. We used optical recording of Ca²⁺ influx through TRPV1 to measure activity and mobility of single TRPV1 molecules in isolated dorsal root ganglion neurons and cell lines. The opening of single TRPV1 channels produced sparklets, representing localized regions of elevated Ca²⁺. Unlike sparklets reported for L-type Ca²⁺ channels, TRPV4 channels, and AchR channels, TRPV1 channels diffused laterally in the plasma membrane as they gated. Mobility was highly variable from channel-to-channel and, to a smaller extent, from cell to cell. Most surprisingly, we found that mobility decreased upon channel activation by capsaicin, but only in the presence of extracellular Ca²⁺. We propose that decreased mobility of open TRPV1 could act as a diffusion trap to concentrate channels in cell regions with high activity.

Article and author information

Author details

Eric N Senning

Department of Physiology and Biophysics, University of Washington, Seattle, United States

Competing interests
The authors declare that no competing interests exist.
Sharona E Gordon

Department of Physiology and Biophysics, University of Washington, Seattle, United States

For correspondence
seg@u.washington.edu

Competing interests
The authors declare that no competing interests exist.

Ethics

Animal experimentation: Many local labs generating transgenic mice have a surplus of wild-type littermates that are euthanized after phenotyping. We have arranged to be present during the euthanasia process and immediately take the carcass for harvesting of the tissue we require. These arrangements are consistent with the principle of reducing the total number of animals used in biomedical experimentation and are approved by AALAC and the University of Washington IACUC.

Copyright

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.