Cytochalasins Actin depolymerization

Furukawa, K., and Mattson, M.E. 1995. Cytochalasins protect hippocampal neurons against amyloid beta-peptide toxicity evidence that actin depolymerization suppresses Ca2+ influx. JNeurochem 65, 1061-1068. 

Thread-like actin filaments (microfilaments) spread through the hepatocytes creating a three-dimensional network and ensuring both form and stability of the cell. They also guarantee the shape of the microvilli and fenestrae as well as supporting the mechanical functions of the canaliculi. In addition, they influence the viscosity of the cytoplasm. Cytochalasin A depolymerizes... 

Cytochalasins are produced by fungi and show various effects on eukaryotic cells. They bound to actin and induced actin depolymerization [135]. Their structural skeletons are each composed of a macrocyclic ring with a fused hydrogenated isoindole. Several compounds having 12- or 14- or 15-membered ring macrocyclic lactones are numbered among the cytochalasins. 

Cytochalasin B Natural product from the fungus Helminthosporium dematioideum (58). Depolymerizes actin hlaments. 

Cytochalasins, drugs that inhibit cellular processes that require actin polymerization and depolymerization (e.g., phagocytosis, cytokinesis, clot retraction, etc.), also act by severing and capping actin filaments. Actin filaments can be stabilized by phalloidin, derived from the poisonous mushroom Amanita phalloides. Assembly of actin filaments into bundles (as in microvilli) and three-dimensional networks is accomplished by two groups of cross-linking proteins (Table 21-6). 

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