Spatial Organization of Gas Vesicles is Governed by Phase-separable GvpU

Gas vesicles (GVs) are microbial protein organelles that support cellular buoyancy, and the recent engineering of GVs has led to multiple applications including reporter gene imaging, acoustic control, and payload delivery. GVs often cluster into a honeycomb pattern to minimize their occupancy of cytosolic space; however, the molecular mechanism behind this process and its influence on cellular physiology remain unknown. Here, we identified GvpU as the protein governing this process. GvpU-mediated clustering is selective to the genotype of GVs, allowing the design of GV variants with genetically encodable clustering states. Furthermore, we uncovered that the clustering is modulated by phase transition behaviors encoded in the intrinsically disordered region of GvpU through a balanced contribution of acidic and aromatic residues, and such phase transition can directly modulate cellular fitness. Collectively, our findings elucidate the protein player, molecular mechanism, and functional roles of GV clustering, and its programmability for biomedical applications.