Preferential blockade of the tubulin transport by colchicine

Abstract

L-[35S]Methionine was injected into the dorsal root ganglion (L5) of the adult rat, and migration of the neurofilament polypeptides (the triplet with molecular weights of 200,000, 160,000 and 68,000 daltons), alpha- and beta-tubulins and actin in the sciatic nerve and the dorsal root was quantitatively determined and also examined by fluorography. Colchicine (4 microgram) injected into the ganglion 10 min before methionine preferentially blocked the tubulin transport, with little if any blockade of the triplet and actin. Colchicine at this dose had no effects on the incorporation of L-[14C]leucine into the total protein and also into tubulins. In contrast to colchicine, vinblastine sulphate (4 microgram) injected into the ganglion in a similar way blocked the transport of all the triplet, tubulins and actin. Cytochalasin D (1 microgram) had no effect on the slow axoplasmic transport.