Isolation of a new actin‐binding protein from dictyostelium discoideum

John Condeelis, Stephen Geosits, Maryanne Vahey

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


A new actin binding protein has been purified to homogeneity from amoebae of Dictyostelium discoideum. This protein is a single polypeptide with a molecular weight of 120,000 upon sodium dodecyl sulfate gel electrophoresis. It is soluble and trypsin‐sensitive, contains no carbohydrate, increases the viscosity and sedimentation rate of F actin, and inhibits the actin‐stimulated Mg ATPase of rabbit muscle heavy meromyosin. The interaction of 120,000‐dalton protein with F actin is not inhibited by millimolar ATP, pyrophosphate, or micromolar calcium. The 120,000‐dalton actin binding protein increases the initial rate of actin polymerization and decreases the critical concentration of actin at steady state. These properties demonstrate that 120,000‐dalton protein from Dictyostelium discoidum is not a myosinlike protein. Rather, this protein is probably involved in regulating the assembly of the actin cytoskeletion.

Original languageEnglish (US)
Pages (from-to)273-285
Number of pages13
JournalCell Motility
Issue number3
StatePublished - 1982


  • F‐actin nucleation
  • actin gelation

ASJC Scopus subject areas

  • Cell Biology


Dive into the research topics of 'Isolation of a new actin‐binding protein from dictyostelium discoideum'. Together they form a unique fingerprint.

Cite this