The Caulobacter cell cycle: timing, spatial organization and checkpoints.

In Caulobacter crescentus, a complex regulatory network integrates temporal and spatial information to control the ordered progression of the cell cycle, and to synchronize cell proliferation with development. Periodicity includes the timed synthesis, activation or destruction of key regulatory proteins, which activate a large number of genes at the appropriate time of the cell cycle. Checkpoints serve to couple cell division and polar development to the replication and segregation state of the chromosome. Asymmetrically positioned regulatory components are involved in the sequential positioning of polar organelles. New work sheds light on the spatial organization of cellular components involved in cell cycle progression and polar differentiation, and starts to define the molecular nature of checkpoints involved in cell cycle control and development.