Scaffold-Scaffold Interaction Facilitates Cell Polarity Development in Caulobacter crescentus
Ning Lü, Samuel W. Duvall, Guohong Zhao, Kimberley A. Kowallis, Chao Zhang, Wei Tan, Jingxian Sun, Haley N. Petitjean, Dylan T. Tomares, Guoping Zhao, W. Seth Childers, Wei Zhao
Abstract
Caulobacter crescentus is a well-established bacterial model to study asymmetric cell division for decades. During cell development, the polarization of scaffold protein PopZ from monopolar to bipolar plays a central role in C. crescentus asymmetric cell division. Nevertheless, the spatiotemporal regulation of PopZ has remained unclear. Here, we demonstrate that the new pole scaffold PodJ functions as a regulator in triggering PopZ bipolarization. The primary regulatory role of PodJ was demonstrated in parallel by comparing it with other known PopZ regulators, such as ZitP and TipN. Physical interaction between PopZ and PodJ ensures the timely accumulation of PopZ at the new cell pole and the inheritance of the polarity axis. Disruption of the PodJ-PopZ interaction impaired PopZ-mediated chromosome segregation and may lead to a decoupling of DNA replication from cell division during the cell cycle. Together, the scaffold-scaffold interaction may provide an underlying infrastructure for cell polarity development and asymmetric cell division.