BioProject

Cell fate determination in the asymmetric bacterium Caulobacter crescentus (Caulobacter) is triggered by the localization of the developmental regulator SpmX to the old (stalked) cell pole during the G1-S transition. More...

Cell fate determination in the asymmetric bacterium Caulobacter crescentus (Caulobacter) is triggered by the localization of the developmental regulator SpmX to the old (stalked) cell pole during the G1-S transition. While SpmX is required to localize and activate the cell fate-determining kinase DivJ at the stalked pole in Caulobacter, it is also required for organelle (stalk) positioning in the cousin Asticaccaulis. We unearth the conserved s54-dependent transcriptional activator regulator TacA as global regulator in Caulobacter whose activation by phosphorylation is indirectly down-regulated by SpmX. Using a combination of forward genetics and cytological screening we uncover a previously uncharacterized and polarized component (SpmY) of the TacA phosphorylation control system, and we show that the SpmY function and localization is conserved. Thus, we demonstrate that SpmX organizes a site-specific, ancestral and multi-functional regulatory hub whose function includes the coordinated control of two co-oscillating global transcriptional regulators, CtrA and TacA. Overall design: Examination of 2 transcription factors occupancy in WT and two mutant backgrounds + assessment of synthetic lethal and viable genes in WT and one null-allele background Less...