Electron microscopic localization of myosin II and ABP‐120 in the cortical actin matrix of Dictyostelium amoebae using IgG‐gold conjugates

S. Ogihara, J. Carboni, J. Condeelis

Research output: Contribution to journalArticle

16 Scopus citations


To narrow the field of possible functions of an actin‐binding protein (ABP‐120) and myosin II, we have used high resolution immunocytochemistry with IgG‐colloidal gold conjugates to identify the types of actin containing structures with which these proteins are associated in the isolated cell cortex. Staining for myosin II and ABP‐120 is associated with distinct regions of the actin cytoskeleton in isolated cortices. Myosin II is localized to lateral arrays of filaments, where it is clustered and has a density that is unrelated to distance from the plasma membrane. Staining for myosin II is associated also with unidentified cytoplasmic vesicles. However, staining for ABP‐120 is concentrated in dense networks of branched microfilaments that are adjacent to the plasma membrane or in surface projections (residual pseudopods and lamellopods). These results are consistent with a role for ABP‐120 in the formation of filament networks in vivo and further suggest that networks of branched microfilaments are unlikely to participate in motility that is mediated by myosin II.

Original languageEnglish (US)
Pages (from-to)505-520
Number of pages16
JournalDevelopmental Genetics
Issue number4-5
Publication statusPublished - 1988



  • Dictyostelium discoideum
  • cell motility
  • pseudopod extension

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology
  • Cell Biology

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