Polarity and cell fate asymmetry in Caulobacter crescentus

► Replicative asymmetry of Caulobacter daughter cells is dictated by CtrA. ► Two phosphorelays drive the phosphorylation and proteolytic stabilization of CtrA. ► CckA, the kinase for CtrA, must localize to a cell pole for maximal activation. ► CckA colocalizes with the phosphatase PleC to avoid downregulation by DivK∼P. ► Localization of DivJ and PleC to opposite poles helps establish replicative asymmetry.