Active Transport of Membrane Components by Self-Organization of the Min Proteins

Heterogeneous distribution of components in the biological membrane is critical in the process of cell polarization. However, little is known about the mechanisms that can generate and maintain the heterogeneous distribution of the membrane components. Here we report that the propagating wave patterns of the bacterial Min proteins can impose corresponding steric pressure on the membrane to establish a directional accumulation of the membrane components, resulting in segregation of the components in the membrane. The diffusivity, influenced by the membrane anchor of the component, and the repulsed ability, influenced by the steric property of the soluble region of the component and molecular crowding, determine the differential spatial distribution of the component in the membrane. Thus, transportation of the membrane components by the Min proteins follows a simple physical principle, which resembles a linear peristaltic pumping process, to selectively segregate and maintain heterogeneous distribution of materials in the membrane.