A team of the Centro de Investigaciones Biológicas (CIB-CSIC) led by Dr. Germán Rivas has recently described in EMBO Reports the mechanism by which essential elements of the bacterial cell division machinery assemble into dynamic condensates by liquid-liquid phase separation in cell-like crowded conditions. These findings suggest that phase-separated biomolecular condensation may also help to organize intracellular space in bacteria.
The essential bacterial cell division protein FtsZ forms phase-separated condensates in the presence of nucleoprotein complexes organized by the SlmA protein, a spatial regulator of FtsZ.
Monterroso et al. have shown that the condensates are dynamic and disband upon GTP-dependent reversible formation of FtsZ fibers whose lifetimes are significantly shortened by SlmA. Condensates are observed in cell-like crowding conditions in solution and inside phase-separated systems encircled by a lipid membrane.
These findings, which are the result of an international collaboration of the CIB group with the laboratories of William Margolin (McGovern Medical School, Universidad de Texas, Houston) and Christine Keating (Pennsylvania State University), suggest that phase-separated FtsZ condensates may constitute a novel element of spatiotemporal organization of essential bacterial cell cycle processes.
Reference: Bacterial division FtsZ protein forms phase-separated condensates with its nucleoid-associated inhibitor SlmA. Begoña Monterroso, Silvia Zorrilla, Marta Sobrinos-Sanguino, Miguel A. Robles-Ramos, Marina López-Álvarez, William Margolin, Christine D Keating, Germán Rivas. EMBO Rep. (2018) Dec 6. pii: e45946. doi: 10.15252/embr.201845946.