Kainate reversibly aggregates brain tubulin in vitro

The effect of kainate, an heterocyclic analogue of glutamate on tubulin polymerization was studied. We demonstrate that kainate induces a dose-dependent aggregation of rat brain tubulin either purified by DEAE-Sephadex A-50 or in the presence of MAPs into a mesh-like structure. Such polymer is cold-, CaCl2- and colchicine-insensitive. Removal of kainate from the incubation medium yields free tubulin competent for polymerizing into normal microtubules in the presence of GTP.