Hydro-osmotic instabilities in active membrane tubes

TL;DR

This paper investigates a novel osmotic pressure-driven instability in active membrane tubes caused by ion pumps, which may explain certain cellular organelle behaviors and has a natural wavelength consistent with biological observations.

Contribution

It introduces a new type of peristaltic instability driven by osmotic pressure in active membrane tubes, distinct from tension-driven instabilities.

Findings

Identifies a pressure-driven peristaltic instability in membrane tubes.

Shows the instability's wavelength matches biological observations.

Suggests relevance to membrane organelle function and biogenesis.

Abstract

We study a membrane tube with unidirectional ion pumps driving an osmotic pressure difference. A pressure driven peristaltic instability is identified, qualitatively distinct from similar tension-driven Rayleigh type instabilities on membrane tubes. We discuss how this instability could be related to the function and biogenesis of membrane bound organelles, in particular the contractile vacuole complex. The unusually long natural wavelength of this instability is in agreement with that observed in cells.