Expression of a gene-encoded FtsZ-based minimal machinery to drive synthetic cell division

Abstract

The Christophe Danelon lab is involved in the long-term effort to construct an autonomous minimal cell using a bottom-up approach. Our goal is to achieve self-maintenance, selfreproduction, and evolution of a liposome compartment containing a minimal genome and a cell-free gene expression system. Self-reproduction requires splitting of the mother compartment into two daughter cells. The project described in this dissertation is part of the group’s attempts to create a minimal division unit for the synthetic cell. The development of a gene-driven, controllable, content-preserving liposome division strategy is an ongoing challenging task. Here, we reconstituted some of the organizational mechanisms for division of Escherichia coli in a cell-free system. In E. coli, cytokinesis is mediated by a multiprotein complex that forms a contractile ring-like structure at the division site. The ring is composed of the cytosolic filament-forming protein FtsZ, as well as its membrane anchoring proteins FtsA and ZipA. The Min system assists in the ring localization at mid-cell by oscillating from pole to pole. Using liposomes as a synthetic compartment and PURE system for cell-free gene expression, we reconstituted membrane-bound cytoskeletal structures and oscillating gradients of Min proteins for liposome constriction and dynamic organization of FtsZ filaments.