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A Time-Efficient Fluorescence Spectroscopy-Based Assay for Evaluating Actin Polymerization Status in Rodent and Human Brain Tissues
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[Effect of phalloidin on the contractile structures in cytoplasmic preparations of Amoeba proteus]

M Paulin-Levasseur, C Gicquaud

    European Journal of Cell Biology
    |December 1, 1981
    PubMed

    Insights

    Phalloidin treatment reveals abundant actin filaments in Amoeba proteus cytoplasm, crucial for cell movement. Higher concentrations halt cytoplasmic streaming by forming actin fibrils.

    Area of Science:

    • Cell biology
    • Biochemistry

    Context:

    • Amoeba proteus is a model organism for studying cellular motility.
    • Understanding the role of actin and myosin in cytoplasmic movement is fundamental to cell biology.

    Purpose:

    • To investigate the effect of phalloidin on the ultrastructure of cytoplasmic components involved in movement in Amoeba proteus.
    • To elucidate the role of F-actin filaments and myosin rods in cellular locomotion.

    Summary:

    • Phalloidin treatment of Amoeba proteus cytoplasmic preparations revealed a dose-dependent effect on F-actin filaments.
    • At concentrations between 2 X 10(-6) M and 5 X 10(-6) M, phalloidin induced the formation of numerous F-actin filaments, some branched and interconnected.
    • Higher phalloidin concentrations led to the aggregation of F-actin into fibrils, inhibiting cytoplasmic movement, while myosin rods remained unaffected.

    Impact:

    • This study clarifies the critical role of F-actin polymerization and organization in amoeboid movement.
    • The findings provide insights into the mechanism of phalloidin's effect on the cytoskeleton.
    • Establishes phalloidin as a useful tool for studying actin dynamics in cell motility research.

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