Chromosome movement in lysed mitotic cells is inhibited by vanadate.

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Abstract
Mitotic PtK1 cell [rat kangaroo kidney], lysed at anaphase into a carbowax 20 M Brij 58 solution, continued to move chromosomes toward the spindle poles and move the spindle poles apart at 50% in vivo rates for 10 min. Chromosome movements were blocked by adding metabolic inhibitors to the lysis medium. Inhibition of movement was reversed by adding ATP to the medium. Vanadate at micromolar levels reversibly inhibits dynein ATPase activity and movement of demembranated flagella and cilia. It does not affect glycerinated myofibril contraction or myosin ATPase activity at less than millimolar concentrations. Vanadate at 10-100 .mu.M reversibly inhibits anaphase movement of chromosomes and spindle elongation. After lysis in vanadate, spindles lose their fusiform appearance and become more barrel shaped. In vitro microtubule polymerization was insensitive to vanadate.