Organization of intermediate filaments in cultured fibroblasts upon disruption of microtubules by cold treatment.

We studied the effect of microtubule-disrupting drugs and cold treatment on the organization of cytoplasmic microtubules and intermediate filaments by the indirect immunofluorescence (IFL) technique. Treatment of the cultured fibroblasts with demecolcine brought about a rapid and complete disruption of microtubules and a concomitant redistribution of intermediate filaments into coiling perinuclear bundles. Cold-treatment of the cells resulted also in a complete disappearance of microtubules but did not cause any change in the distribution of intermediate filaments. During the reorganization process of the cytoplasmic microtubular complex, apparently normal arrays of intermediate filaments were discernible in the cells. The results show that microtubules can undergo a disruption-reorganization process without changes in the organization of intermediate filaments and suggest that the maintenance of normal intermediate filament organization is independent of microtubules.