Interaction of estramustine phosphate with microtubule-associated proteins

AbstractWe have reported [(1984) Cancer Res., in press] that estramustine phosphate inhibits microtubule assembly and disassembled preformed microtubules. We now present evidence that estramustine phosphate inhibits microtubule assembly by binding to the microtubule-associated proteins. We have found that: (1) additional microtubule-associated proteins relieved the inhibition of assembly by estramustine phosphate; (2) 3H-labelled estramustine phosphate bound predominantly to the microtubule-associated proteins; and (3) the content of the microtubule-associated proteins was reduced in taxol reversed estramustine phosphate-inhibited microtubules