Tyrosinated, but not detyrosinated, alpha-tubulin is present in root tip cells

The distribution of tyrosinated and detyrosinated tubulin in microtubule ar rays of pine and onion cells was investigated by immunofluorescence techniq ues. Staining of isolated cells and methacrylate sections of Pinus radiata and Allium cepa root tips indicated that all microtubule structures contain ed tyrosinated tubulin but not the posttranslationally modified detyrosinat ed tubulin. The detyrosinated tubulin epitope was however, created in vitro by treating both sections and fixed whole cells with carboxypeptidase A.