An intracellular compass spatially coordinates cell cycle modules in Caulobacter crescentus.

Cellular functions in Bacteria, such as chromosome segregation and cytokinesis, result from cascades of molecular events operating largely as self-contained modules. Regulated timing of these cellular modules stems from global genetic circuits that allow precise temporal activation with respect to cell cycle progression and cell differentiation. Critically, many of these functions occur at defined locations within the cell, and therefore regulators of each module must communicate to remain coordinated in space. In this perspective, we highlight recent discoveries in Caulobacter crescentus asymmetric cell division to illuminate diverse mechanisms by which a cellular compass, composed of scaffolding and signaling proteins, directs cell cycle modules to their exact cellular addresses.