DETECTION, DISTRIBUTION AND AMOUNT OF POSTTRANSLATIONAL α- TUBULIN MODIFICATIONS IN IMMORTALIZED RAT SCHWANN CELLS

Microtubules (MTs), heterodimers of α- and β-tubulin, are involved in different cellular processes including mitosis, cell motility, intracellular transport, cell shape and polarization. In most eukaryotes tubulins, especially the α, are subjected to several post-translational modifications (PTMs) which include acetylation, tyrosination, detyrosination, Δ2 modification, polyglutamylation, that characterize different type of MTs and regulate the interactions between MTs and certain MAPs or motor proteins. Despite neurons, in which presence and distributions of tubulin PTMs are well evaluated, in glial cells like Schwann cells, little is known about the diverse tubulin PTMs amount, distribution and their functional role. So that, the purpose of the present work was to deepen the knowledge about the diverse tubulin PTMs in a commonly used immortalized Schwann cell line. By Western blot analysis we found a higher amount of polyglutamylated and tyrosinated α-tubulin, whereas acetylated, Δ2 and detyrosinated α-tubulin were less expressed. Immunofluorescence staining, highlighted the distribution of acetylated and detyrosinated α-tubulin along the Schwann cells prolongations. In contrast, polyglutamylated α-tubulin was more detectable close to the cell body of Schwann cells, whereas the Δ2-modification was mainly distributed round the nuclear profile. Summing up, our investigation offers insight on several tubulin PTMs amount and distribution in Schwann cells. This could be a further contribution to better understand the role played by different MTs in Schwann cells biology and during the onset of certain disorders of peripheral nervous system.