Binding of Microtubule Proteins to DNA: Specificity of the Interaction

Abstract

Tubulin is detected among the DNA-binding proteins when an extract from [hamster] fibroblasts is chromatographed on DNA-cellulose. Further purification of the colchicine-binding activity shows that purified tubulin from fibroblasts does not bind to DNA. Depolymerized [pig] brain microtubule proteins show a high affinity for DNA. The fraction bound is composed of tubulin and microtubule-associated proteins. Experiments with fractionated microtubule proteins indicate that tubulin-free microtubule-associated proteins bind to DNA, while tubulin free of microtubule-associated proteins does not. Microtubule-associated proteins bind better to eukaryotic than to phage DNA suggesting a specificity of the interaction.