Calcium-calmodulin regulated effectors of microtubule stability in bovine brain

Stable microtubules (as defined by resistance to Ca 2+ , drug or cold temperature induced disassembly) form in abundance during tubulin assembly in brain crude extracts. We have previously shown that, in rat brain crude extracts, all microtubule stabilizing activity could be ascribed to a single Ca 2+ -calmodulin binding and Ca 2+ -calmodulin regulated protein, called «stable tubule only polypeptide», STOP 145 [Pirollet, F., Rauch, C. T., Job, D., & Margolis, R. L. (1989) Biochemistry 78, 835-842]