Gating-by-tilt of mechanosensitive membrane channels

TL;DR

This paper introduces a novel gating mechanism for membrane channels based on membrane tilt changes, which explains sensitivity to membrane asymmetry and tension, differing from traditional models.

Contribution

It proposes gating-by-tilt as an alternative to existing models, highlighting its ability to account for membrane asymmetry effects on channel gating.

Findings

Energy difference between states exceeds kBT under biological tension

Gating-by-tilt explains sensitivity to leaflet asymmetries

Mechanism aligns with experimental observations

Abstract

We propose an alternative mechanism for the gating of biological membrane channels in response to membrane tension that involves a change in the slope of the membrane near the channel. Under biological membrane tensions we show that the energy difference between the closed (tilted) and open (untilted) states can far exceed kBT and is comparable to what is available under simple ilational gating. Recent experiments demonstrate that membrane leaflet asymmetries (spontaneous curvature) can strong effect the gating of some channels. Such a phenomenon would be more easy to explain under gating-by-tilt, given its novel intrinsic sensitivity to such asymmetry.