GLUTAMYLATION OF CENTRIOLE AND CYTOPLASMIC TUBULIN IN PROLIFERATING NONNEURONAL CELLS

We have examined the distribution of glutamylated tubulin in non-neuro nal cell lines. A major part of centriole tubulin is highly modified o n both the alpha- and beta-tubulin subunits, whereas a minor part of t he cytoplasmic tubulin is slightly modified, on the beta-tubulin only. Furthermore, we observed that tubulin glutamylation varies during the cell cycle: an increase occurs during mitosis on both centriole and s pindle microtubules. In the spindle, this increase appears more obviou s 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 describ ed tubulin modifications. The functional significance of this distribu tion is discussed. (C) 1998 Wiley-Liss, Inc.