Proc. Natl Acad. Sci. USA (2017)

Like life's little filing cabinet, the cell functions by compartmentalizing its contents, often in discrete volumes bound with a membrane of their own. In order to form these compartments, cells need to undergo membrane fission, a process that has been associated with the structural oddities of certain proteins — including ring motifs, helices and hydrophobic insertions. Now, Wilton Snead and colleagues have found evidence to suggest that any protein — regardless of its structure — may be capable of mediating membrane fission, by generating steric pressure through collisions.

Hydrophobic inclusions in membrane-binding proteins are thought to facilitate fission by helping to bend the membrane. But the study by Snead et al. supports the notion that this hydrophobicity might have more of an incidental role. Using fluorescence resonance energy transfer techniques, the authors found that fission efficiency was actually independent of hydrophobicity. Instead, they saw that fission became spontaneous with increases in steric pressure derived from protein crowding, implying that these inclusions may function to simply enhance the pressure that drives membrane fission.