Lipopolysaccharide-caused fragmentation of individual microtubules in vitro observed by video-enhanced differential interference contrast microscopy

Microtubule disassembly is commonly believed to be a process of endwise tubulin dimer release. The present study demonstrates by video interference contrast microscopy that Escherichia coli lipopolysaccharide (LPS) caused microtubule disassembly in vitro by both endwise shortening and fragmentation. In contrast, the microtubules were only shortened from their ends in the presence of DNA, used as another example of a macromolecular microtubule effector. LPS-caused microtubule fragmentation was confirmed by transmission electron microscopy. Because of its ability to induce both fragmentation and endwise shortening, LPS, which is involved in sepsis pathogenesis, has to be regarded as a highly active microtubule-destabilizing agent. (C) 1998 Federation of European Biochemical Societies.