Membrane Thickness Sensitivity of Avian Prestin: Implications

TL;DR

This paper investigates how avian prestin's function is influenced by membrane thickness, proposing a mechanism involving membrane shearing deformation that explains its sensitivity despite lacking detectable area changes.

Contribution

It introduces a novel hypothesis that avian prestin's motile function involves membrane shearing deformation, differing from mammalian prestin's area change mechanism.

Findings

Avian prestin is sensitive to membrane thickness similar to mammalian prestin.

Proposes shearing deformation as a basis for avian prestin's motility.

Suggests a different conformational transition mechanism for avian prestin.

Abstract

Avian prestin is sensitive to membrane thickness as much as mammalian prestin, which undergoes conformational transitions in membrane area and thereby drives length changes of the cylindrical cell body of outer hair cells. The membrane thickness dependence of mammalian prestin stems from changes in hydrophobic profile in conformational states, accompanied by changes in their membrane area. Even though such area changes are not detected for avian prestin, it nonetheless bends hair bundles of avian short hair cells. Here it is suggested that the motile function of avian prestin can be based on conformational transitions involving shearing deformation of the membrane protein, which also leads to membrane thickness sensitivity.