Figure 1.

Overview of asymmetric cell division and spatial perturbation of cell fate proteins in C. crescentus. (a) The spatial and temporal dynamics of cell fate proteins in the bacterial cell cycle. The cell cycle begins with a swarmer cell with PleC, a phosphatase localized at the flagellum pole. After entering DNA replication, S phase, the swarmer cell differentiates into a stalked cell. As cell cycle progresses from S to G2 phase, dividing cells asymmetrically segregate DivJ, a histidine kinase and PleC to stalked and swarmer cells, respectively; (b) PleC and DivJ play opposite roles in the dephosphorylation and phosphorylation of DivK, dephosphorylated DivK triggers a signaling cascade leading to the accumulation of CtrA~P which blocks transition into S phase; (c) Schematic design of co-localizing two different cell fate proteins at the same pole. Membrane-bound proteins PleC or DivJ are fused with GBD peptide and cytoplasmic DivK is tagged with SH3 peptide. Scaffold proteins expressing SH3 and GBD domains are driven by xylose-inducible promoter and therefore can be induced upon addition of xylose to culture media; (d) Four possible scenarios and corresponding phenotypic outcomes after perturbation of cell fate proteins by scaffolds.