Cofilin-2, a novel type of cofilin, is expressed specifically at aggregation stage of Dictyostelium discoideum development

Genes Cells. 2001 Oct;6(10):913-21. doi: 10.1046/j.1365-2443.2001.00470.x.

Abstract

Background: A conventional cofilin, cofilin-1 in Dictyostelium discoideum plays significant roles in cell proliferation, phagocytosis, chemotactic movement and macropinocytosis.

Results: We identified a new member of the cofilin family, named cofilin-2 in D. discoideum. Cofilin-2 shows significant homology to a conventional Dictyostelium cofilin, cofilin-1, through its entire sequence, and contains residues conserved among the cofilin family that are responsible for actin-binding. On the other hand, several residues that are conserved among the cofilin family are missing from cofilin-2. Purified cofilin-2 depolymerized actin filaments in a dose- and pH-dependent manner and reduced the apparent viscosity of an actin solution, although they did not co-sediment with actin filaments at all. Cofilin-2 was not expressed in vegetative cells, but was transiently induced during the aggregation stage of development, whereas cofilin-1 was predominantly expressed in vegetative cells. Immunocytochemistry revealed that cofilin-2 localizes at substrate adhesion sites, where cofilin-1 is almost completely excluded. Disruption of the cofilin-2 gene caused an increase in actin accumulation at the substrate adhesion sites. We also found that cofilin-2 did not rescue Deltacof1 yeast cells, whereas cofilin-1 did.

Conclusions: Cofilin-2 may play a distinct role from that of cofilin-1 in destabilization of the actin cytoskeleton during Dictyostelium development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Depolymerizing Factors
  • Actins / metabolism
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Adhesion
  • Cofilin 2
  • Cytoskeleton / metabolism
  • Dictyostelium / genetics*
  • Dictyostelium / growth & development*
  • Gene Expression Regulation, Developmental
  • Microfilament Proteins / genetics*
  • Microfilament Proteins / metabolism
  • Molecular Sequence Data
  • Mutation
  • Sequence Homology, Amino Acid
  • Yeasts / genetics

Substances

  • Actin Depolymerizing Factors
  • Actins
  • Cofilin 2
  • Microfilament Proteins

Associated data

  • GENBANK/AB055926