Structural and functional alterations in microtubule protein from Chinese hamster ovary cell mutants.

Abstract

Mutant lines of Chinese hamster ovary cells were examined that have increased resistance to the antimicrotubule drug colcemide. Increased tolerance to the drug in vivo is reflected in altered properties of microtubules and tubulin in vitro. One series of related mutants were examined and had different microtubule alterations associated with each selection step. These changes include decreased colcemide-binding affinity, an altered electrophoretic pattern of tubulin subcomponents, increased resistance to colcemide inhibition of polymerization in vitro and a decreased critical concentration for microtubule assembly. Characterized mutants of the class described here will be useful for probing the regulation of microtubule assembly in vivo.