Destruction of microfilament bundles in mouse embryo fibroblasts treated with inhibitors of energy metabolism
Bershadsky, A.D.; Gelfand, V.I.; Svitkina, T.M.; Tint, I.S.
Experimental Cell Research 127(2): 421-429
Immunofluorescence with an antiactin antibody and EM were used to study the distribution of actin in cultured mouse fibroblasts during treatment with inhibitors of energy metabolism [sodium azide carbonylcyanide-m-chlorophenylhydrazone,2,4-dinitrophenol and oligomycin]. The inhibitors induce gradual disorganization of actin-containing microfilament bundles. At the 1st stage of the process the bundles degrade into separate fragments; later only small patches of actin can be found in the inhibitor-treated cells. This transformation takes about 90 min and is fully reversible as microfilament bundles are recovered after incubation of the cells in the inhibitor-free growth medium. The inhibitors do not alter actin distribution in the presence of glucose. Their action apparently is due to a reduction of the ATP level in the cells. A 90 min incubation with the inhibitors does not markedly alter either the cell shape or the microtubule system. Inhibitors of the energy metabolism prevent cytochalasin action on cells. Cytochalasin B or cytochalasin D rapidly disorganize the microfilament bundles and cause cell arborization. Microfilament bundle destruction in the cells incubated in the mixture of cytochalasin and any of the inhibitors requires 90 min and is not accompanied by dramatic changes in the cell morphology, so the process is indistinguishable from microfilament bundle destruction in the presence of the inhibitors alone.