A multi-layered protein network stabilizes the Escherichia coli FtsZ-ring and modulates constriction dynamics

PLoS Genet. 2015 Apr 7;11(4):e1005128. doi: 10.1371/journal.pgen.1005128. eCollection 2015 Apr.

Abstract

The prokaryotic tubulin homolog, FtsZ, forms a ring-like structure (FtsZ-ring) at midcell. The FtsZ-ring establishes the division plane and enables the assembly of the macromolecular division machinery (divisome). Although many molecular components of the divisome have been identified and their interactions extensively characterized, the spatial organization of these proteins within the divisome is unclear. Consequently, the physical mechanisms that drive divisome assembly, maintenance, and constriction remain elusive. Here we applied single-molecule based superresolution imaging, combined with genetic and biophysical investigations, to reveal the spatial organization of cellular structures formed by four important divisome proteins in E. coli: FtsZ, ZapA, ZapB and MatP. We show that these interacting proteins are arranged into a multi-layered protein network extending from the cell membrane to the chromosome, each with unique structural and dynamic properties. Further, we find that this protein network stabilizes the FtsZ-ring, and unexpectedly, slows down cell constriction, suggesting a new, unrecognized role for this network in bacterial cell division. Our results provide new insight into the structure and function of the divisome, and highlight the importance of coordinated cell constriction and chromosome segregation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Carrier Proteins / metabolism
  • Cell Cycle Proteins / metabolism
  • Cell Division*
  • Chromosomal Proteins, Non-Histone / metabolism
  • Cytoskeletal Proteins / metabolism*
  • Escherichia coli / metabolism*
  • Escherichia coli / physiology
  • Escherichia coli / ultrastructure
  • Escherichia coli Proteins / metabolism
  • Motion

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Cytoskeletal Proteins
  • Escherichia coli Proteins
  • FtsZ protein, Bacteria
  • MatP protein, E coli
  • ZapA protein, E coli
  • ZapB protein, E coli