Referenced in: none

Automatically associated channels: Kv2.1

Title: FMRFamide and membrane stretch as activators of the Aplysia S-channel.

Authors: D H Vandorpe, D L Small, A R Dabrowski, C E Morris

Journal, date & volume: Biophys. J., 1994 Jan , 66, 46-58

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/7510529

Abstract
The long-standing distinction between channels and transporters is becoming blurred, with one pump protein even able to convert reversibly to a channel in response to osmotic shock. In this light, it is plausible that stretch channels, membrane proteins whose physiological roles have been elusive, may be transporters exhibiting channel-like properties in response to mechanical stress. We recently described a case, however, where this seems an unlikely explanation. An Aplysia K channel whose physiological pedigree is well established (it is an excitability-modulating conductance mechanism) was found able to be activated by stretch. Here we establish more firmly the identity of this Aplysia conductance, the S-channel, as a stretch channel. We show that the permeation and fast kinetic properties of the stretch-activated channel and of the FMRFamide-activated S-channel are indistinguishable. We have also made progress in extending the kinetic analysis of the stretch channel to situations of multiple channel activity. This analysis implements a novel renewal theory approach and is therefore explained in some detail.