Gelsolin mediates calcium-dependent disassembly of Listeria actin tails

Proc Natl Acad Sci U S A. 2005 Feb 8;102(6):1921-6. doi: 10.1073/pnas.0409062102. Epub 2005 Jan 25.


The role of intracellular Ca2+ in the regulation of actin filament assembly and disassembly has not been clearly defined. We show that reduction of intracellular free Ca2+ concentration ([Ca2+]i) to <40 nM in Listeria monocytogenes-infected, EGFP-actin-transfected Madin-Darby canine kidney cells results in a 3-fold lengthening of actin filament tails. This increase in tail length is the consequence of marked slowing of the actin filament disassembly rate, without a significant change in assembly rate. The Ca2+-sensitive actin-severing protein gelsolin concentrates in the Listeria rocket tails at normal resting [Ca2+]i and disassociates from the tails when [Ca2+]i is lowered. Reduction in [Ca2+]i also blocks the severing activity of gelsolin, but not actin-depolymerizing factor (ADF)/cofilin microinjected into Listeria-infected cells. In Xenopus extracts, Listeria tail lengths are also calcium-sensitive, markedly shortening on addition of calcium. Immunodepletion of gelsolin, but not Xenopus ADF/cofilin, eliminates calcium-sensitive actin-filament shortening. Listeria tail length is also calcium-insensitive in gelsolin-null mouse embryo fibroblasts. We conclude that gelsolin is the primary Ca2+-sensitive actin filament recycling protein in the cell and is capable of enhancing Listeria actin tail disassembly at normal resting [Ca2+]i (145 nM). These experiments illustrate the unique and complementary functions of gelsolin and ADF/cofilin in the recycling of actin filaments.

Publication types

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

MeSH terms

  • Actin Depolymerizing Factors
  • Actins / genetics
  • Actins / metabolism*
  • Animals
  • Calcium / metabolism*
  • Cells, Cultured
  • Chelating Agents / metabolism
  • Egtazic Acid / analogs & derivatives*
  • Egtazic Acid / metabolism
  • Focal Adhesion Kinase 1
  • Focal Adhesion Protein-Tyrosine Kinases
  • Gelsolin / metabolism*
  • Listeria monocytogenes / cytology
  • Listeria monocytogenes / metabolism*
  • Mice
  • Mice, Knockout
  • Microfilament Proteins / metabolism
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Xenopus laevis


  • Actin Depolymerizing Factors
  • Actins
  • Chelating Agents
  • Gelsolin
  • Microfilament Proteins
  • Recombinant Fusion Proteins
  • 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester
  • Egtazic Acid
  • Protein-Tyrosine Kinases
  • Focal Adhesion Kinase 1
  • Focal Adhesion Protein-Tyrosine Kinases
  • Ptk2 protein, mouse
  • Calcium