Immunological homologues of theArabidopsis thaliana ?1 tubulin are polyglutamylated inNicotiana tabacum

Abstract

Peptide-specific antibody AAB1, raised to the C-terminal 13 amino acids ofArabidopsis thaliana β1 tubulin, identifies a single electrophoretically separable β-tubulin on 2-D-gel Western blots of total protein extracts fromA. thaliana seedlings. We show that AAB1 crossreacts with two of the eight polyglutamylated β-tubulin isoforms present in purifiedNicotiana tabacum tubulin fractionated by high-resolution isoelectric focussing. Immunolocalisation studies using AAB1 revealed that the twoN. tabacum polyglutamylated β1-tubulin isoforms are utilised in all four plant microtubule arrays (the interphase cortical array, the preprophase band, the spindle and the phragmoplast) indicating that there is no apparent subcellular sorting of these isotypes.