RodZ: a key-player in cell elongation and cell division in Escherichia coli

Abstract

RodZ is required for determination of cell shape in rod-shaped bacterium, such as Escherichia coli. RodZ is a transmembrane protein and forms a supramolecular complex called the Rod complex with other proteins, such as MreB-actin and peptidoglycan synthesis enzymes (for e.g., PBP2). Deletion of the rodZ gene changes the cell shape from rod to round or ovoid. Another supramolecular complex called divisome that controls cell division mainly consists of FtsZ-tubulin. MreB directly interacts with FtsZ and this interaction is critical to trigger a transition from cell elongation to cell division. Recently, we found that RodZ also directly interacts with FtsZ, and RodZ recruits MreB to the divisome. Formation of the division ring, called Z ring, is delayed if RodZ does not interact with FtsZ, indicating that RodZ might facilitate the formation of the Z ring during the cell division process. In this mini-review, we have summarized the roles of RodZ in cell elongation and cell division, especially based on our recent study.

Keywords: FtsZ; MreB; Rod complex; RodZ; divisome; peptidoglycan.

Figure 1.. RodZ functions. (A) Schematic illustration of the Rod complex. Different components of Rod complex such as, RodZ, MreB, MreC, MreD, PBP2 and RodA are shown. Other components were not shown in this illustration. PG; peptidoglycan, IM; inner membrane. (B) Phase contrast image of WT cells and cells lacking rodZ (ΔrodZ). Scale bar is 2 µm. (C) Schematic illustration of the structure of RodZ. (D) Subcellular localization of RodZ. Phase contrast and fluorescent images of RU1124 cells producing sfGFP-RodZ and ZapA-mCherry grown in the absence and presence of cephalexin. Cells were also stained by Hoechst33342. Arrowheads indicate division site localization of RodZ and ZapA. Scale bar is 2 µm. (E) Model for functions of RodZ in cell elongation and cell division. (i) When a cell elongate, Rod complexes are formed. (ii) The structure of RodZ is changed by MreB to the suitable structure for division site and RodZ localizes to division site through direct interaction with FtsZ. (iii) A cell is contracted by divisome. R; RodZ, M; MreB, F; FtsZ.