Adenine nucleotide-dependent regulation of assembly of bacterial tubulin-like FtsZ by a hypermorph of bacterial actin-like FtsA

J Biol Chem. 2009 May 22;284(21):14079-86. doi: 10.1074/jbc.M808872200. Epub 2009 Mar 17.

Abstract

Cytokinesis in bacteria depends upon the contractile Z ring, which is composed of dynamic polymers of the tubulin homolog FtsZ as well as other membrane-associated proteins such as FtsA, a homolog of actin that is required for membrane attachment of the Z ring and its subsequent constriction. Here we show that a previously characterized hypermorphic mutant FtsA (FtsA*) partially disassembled FtsZ polymers in vitro. This effect was strictly dependent on ATP or ADP binding to FtsA* and occurred at substoichiometric levels relative to FtsZ, similar to cellular levels. Nucleotide-bound FtsA* did not affect FtsZ GTPase activity or the critical concentration for FtsZ assembly but was able to disassemble preformed FtsZ polymers, suggesting that FtsA* acts on FtsZ polymers. Microscopic examination of the inhibited FtsZ polymers revealed a transition from long, straight polymers and polymer bundles to mainly short, curved protofilaments. These results indicate that a bacterial actin, when activated by adenine nucleotides, can modify the length distribution of bacterial tubulin polymers, analogous to the effects of actin-depolymerizing factor/cofilin on F-actin.

Publication types

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

MeSH terms

  • Actins / metabolism*
  • Adenine Nucleotides / metabolism*
  • Adenosine Diphosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Adenylyl Imidodiphosphate / metabolism
  • Bacterial Proteins / metabolism*
  • Bacterial Proteins / ultrastructure
  • Cytoskeletal Proteins / metabolism*
  • Cytoskeletal Proteins / ultrastructure
  • Escherichia coli / enzymology
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / isolation & purification
  • Escherichia coli Proteins / metabolism*
  • GTP Phosphohydrolases / metabolism
  • Histidine / metabolism
  • Hydrogen-Ion Concentration
  • Oligopeptides / metabolism
  • Polymers / metabolism
  • Protein Binding
  • Tubulin / metabolism*

Substances

  • Actins
  • Adenine Nucleotides
  • Bacterial Proteins
  • Cytoskeletal Proteins
  • Escherichia coli Proteins
  • FtsA protein, E coli
  • FtsZ protein, Bacteria
  • His-His-His-His-His-His
  • Oligopeptides
  • Polymers
  • Tubulin
  • Adenylyl Imidodiphosphate
  • Histidine
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • GTP Phosphohydrolases