Subcellular localization of tubulin in chick retina

Tubulin was measured through [3H]colchicine-binding in membrane and soluble components of chick retinal subcellular fractions. Total tubulin content was concentrated in the synaptosomal and rod outer segment fractions. Although in total retinal homogenate only 20% of total tubulin was associated to the membrane, in synaptosomes and photoreceptor outer segments, up to 50% of tubulin was bound to the membrane fraction. Results raise the possibility of tubulin participation in transmembrane phenomena which are common to transmitter release and photoexcitation.