Interactions of Β Tubulin Isotypes with Glutathione in Differentiated Neuroblastoma Cells Subject to Oxidative Stress

Microtubules are a major component of the neuronal cytoskeleton. Tubulin, the subunit protein of microtubules, is an / heterodimer. Both and exist as families of isotypes, whose members are encoded by different genes and have different amino acid sequences. The II and III isotypes are very prominent in the nervous system. Our previous work has suggested that II may play a role in neuronal differentiation, but the role of III in neurons is not well understood. In the work reported here, we examined the roles of the different -tubulin isotypes in response to glutamate/glycine treatment, and found that both II and III bind to glutathione in the presence of ROS, especially III. In contrast, I did not bind to glutathione. Our results suggest that II and III, but especially III, may play an important role in the response of neuronal cells to stress. In view of the high levels of II and III expressed in the nervous system it is conceivable that these tubulin isotypes may use their sulfhydryl groups to scavenge ROS and protect neuronal cells against oxidative stress.