Sanselicio Stefano, Bergé Matthieu, Théraulaz Laurence, Radhakrishnan Sunish Kumar, Viollier Patrick H
Department of Microbiology and Molecular Medicine, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Medicine/CMU, University of Geneva, Rue Michel Servet 1, Genève 4 1211, Switzerland.
Nat Commun. 2015 May 8;6:7005. doi: 10.1038/ncomms8005.
Despite the myriad of different sensory domains encoded in bacteria, only a few types are known to control the cell cycle. Here we use a forward genetic screen for Caulobacter crescentus motility mutants to identify a conserved single-domain PAS (Per-Arnt-Sim) protein (MopJ) with pleiotropic regulatory functions. MopJ promotes re-accumulation of the master cell cycle regulator CtrA after its proteolytic destruction is triggered by the DivJ kinase at the G1-S transition. MopJ and CtrA syntheses are coordinately induced in S-phase, followed by the sequestration of MopJ to cell poles in Caulobacter. Polarization requires Caulobacter DivJ and the PopZ polar organizer. MopJ interacts with DivJ and influences the localization and activity of downstream cell cycle effectors. Because MopJ abundance is upregulated in stationary phase and by the alarmone (p)ppGpp, conserved systemic signals acting on the cell cycle and growth phase control are genetically integrated through this conserved single PAS-domain protein.
尽管细菌中编码了无数不同的感官领域，但已知只有少数几种类型能控制细胞周期。在这里，我们利用对新月柄杆菌运动突变体的正向遗传筛选，鉴定出一种具有多效调节功能的保守单结构域PAS（Per-Arnt-Sim）蛋白（MopJ）。在G1-S期转换时，DivJ激酶触发主细胞周期调节因子CtrA的蛋白水解破坏后，MopJ促进其重新积累。MopJ和CtrA的合成在S期被协同诱导，随后MopJ在柄杆菌中被隔离到细胞极。极化需要柄杆菌DivJ和PopZ极性组织者。MopJ与DivJ相互作用，并影响下游细胞周期效应器的定位和活性。由于MopJ的丰度在稳定期和警报素（p）ppGpp的作用下上调，通过这种保守的单PAS结构域蛋白，作用于细胞周期和生长阶段控制的保守系统信号在遗传上被整合。
