Glutamylation of centriole and cytoplasmic tubulin in proliferating non-neuronal cells

We have examined the distribution of glutamylated tubulin in non‐neuronal cell lines. A major part of centriole tubulin is highly modified on both the α‐ and β‐tubulin subunits, whereas a minor part of the cytoplasmic tubulin is slightly modified, on the β‐tubulin only. Furthermore, we observed that tubulin glutamylation varies during the cell cycle: an increase occurs during mitosis on both centriole and spindle microtubules. In the spindle, this increase appears more obvious on the pole‐to‐pole and kinetochore microtubules than on the astral microtubules. The cellular pattern and the temporal variation of this post‐translational modification contrast with other previously described tubulin modifications. The functional significance of this distribution is discussed. Cell Motil. Cytoskeleton 39:223–232, 1998. © 1998 Wiley‐Liss, Inc.