Nutritional Control of DNA Replication Initiation through the Proteolysis and Regulated Translation of DnaA

• DOI: 10.1371/journal.pgen.1005342
• Publication Date: 2015-07-02T18:03:27Z
• Authors: David J. Leslie; Christian Heinen; Frederic D. Schramm; Marietta Thüring; Christopher D. Aakre; Sean M. Murray; Michael T. Laub; Kristina Jonas
• Keywords: DnaA; Caulobacter crescentus; Proteolysis

Bacteria can arrest their own growth and proliferation upon nutrient depletion under various stressful conditions to ensure survival. However, the molecular mechanisms responsible for suppressing arresting cell cycle such remain incompletely understood. Here, we identify post-transcriptional that help enforce a cell-cycle in Caulobacter crescentus following limitation during entry into stationary phase by limiting accumulation of DnaA, conserved replication initiator protein. DnaA is rapidly degraded Lon protease limitation. rate degradation not significantly altered changes availability. Instead, demonstrate decreased availability downregulates dnaA translation mechanism involving 5' untranslated leader region transcript; Lon-dependent proteolysis then outpaces synthesis, leading elimination DNA replication. Our results how regulated constitutive provide cells means precisely modulating concentration key regulatory proteins response environmental inputs.