Effect of estradiol on the in vitro assembly of rat brain tubulin

Abstract

In order to examine if an interaction existed between estradiol and microtubules, tubulin from rat brain was isolated. Ability of this tubulin preparation to hydrolyse GTP and to assemble into microtubulesin vitro was assessed. Tubulin-induced GTP hydrolysis was observed to occur as almost asingle burst. It was found that estradiol inhibited this GTPase activity of tubulin in a dose-dependentmanner and this inhibition could be overcome by a large excess of GTP. Estradiol also inhibitedthe rate as well as the extent of tubulin assembly in vitro, as assessed by turbidity changesand electron microscopy.