from Stephen C. Smith, Juan-Jesus Vicente and Kathleen R. Ryan writing in Two-Component Systems in Bacteria:
The intricate cell division and developmental cycle of the α-Proteobacterium Caulobacter crescentus has been studied for four decades. During that time, elegant genetic screens and comprehensive post-genomic methods have uncovered a branched network of two-component signaling proteins that orchestrates Caulobacter cell cycle progression and morphological development. In addition to yielding the first and most detailed picture of bacterial cell cycle control, Caulobacter studies have revealed novel ways in which two-component proteins generate cellular outputs, interact with each other, and are themselves regulated.
Further reading: Two-Component Systems in Bacteria