Coiling of intermediate filaments induced by microinjection of a vimentin-specific antibody does not interfere with locomotion and mitosis

Abstract

Microinjection of polyclonal sheep anti-vimentin IgGs purified by affinity chromatography into a rat fibroblastoid line leads to a specific reorganization of the cytoskeleton. Immunofluorescence microscopy shows that cytoplasmic microtubules and microfilaments are unaffected by intermediate filaments collapse and are collected into a tight perinuclear cap containing antibody-crosslinked vimentin filaments. The crosslinking was further documented by electron microscopy after treatment with Triton X-100 and ferritin-labelled anti-sheep IgGs. Inspite of the presence of the caps, which are retained for about 30 h, cells show a normal morphology and are locomotive. The collapsed intermediate filaments do not interfere with subsequent mitosis or with cytokinesis. After mitosis the capped filaments can be distributed either to both daughter cells or to only one of the two daughter cells.