Three-dimensional patterns and redistribution of myosin II and actin in mitotic Dictyostelium cells

Ralph Neujahr, Christina Heizer, Richard Albrecht, Maria Ecke, Jean Marc Schwartz, Igor Weber, Günther Gerisch

    Research output: Contribution to journalArticlepeer-review


    Myosin II is not essential for cytokinesis in cells of Dictyostelium discoideum that are anchored on a substrate (Neujahr, R., C. Heizer, and G. Gerisch. 1997. J. Cell Sci. 110:123-137), in contrast to its importance for cell division in suspension (DeLozanne, A., and J.A. Spudich. 1987. Science. 236:1086-1091; Knecht, D.A., and W.F. Loomis. 1987. Science. 236: 1081- 1085.). These differences have prompted us to investigate the three- dimensional distribution of myosin II in cells dividing under one of three conditions: (a) in shaken suspension, (b) in a fluid layer on a solid substrate surface, and (c) under mechanical stress applied by compressing the cells. Under the first and second conditions outlined above, myosin II does not form patterns that suggest a contractile ring is established in the furrow. Most of the myosin II is concentrated in the regions that flank the furrow on both sides towards the poles of the dividing cell. It is only when cells are compressed that myosin II extensively accumulates in the cleavage furrow, as has been previously described (Fukui, Y., T.J. Lynch, H. Brzeska, and E.D. Korn. 1989. Nature. 341:328-331), i.e., this massive accumulation is a response to the mechanical stress. Evidence is provided that the stress- associated translocation of myosin II to the cell cortex is a result of the dephosphorylation of its heavy chains. F-actin is localized in the dividing cells in a distinctly different pattern from that of myosin II. The F-actin is shown to accumulate primarily in protrusions at the two poles that ultimately form the leading edges of the daughter cells. This distribution changes dynamically as visualized in living cells with a green fluorescent protein-actin fusion.
    Original languageEnglish
    Pages (from-to)1793-1804
    Number of pages11
    JournalJournal of Cell Biology
    Issue number7
    Publication statusPublished - 29 Dec 1997


    Dive into the research topics of 'Three-dimensional patterns and redistribution of myosin II and actin in mitotic Dictyostelium cells'. Together they form a unique fingerprint.

    Cite this