Accumulation of delta 2-tubulin, a major tubulin variant that cannot be tyrosinated, in neuronal tissues and in stable microtubule assemblies

J Cell Sci. 1994 Jun;107 ( Pt 6):1529-43.

Abstract

Tubulin is the major protein component of brain tissue. It normally undergoes a cycle of tyrosination-detyrosination on the carboxy terminus of its alpha-subunit and this results in subpopulations of tyrosinated tubulin and detyrosinated tubulin. Brain tubulin preparations also contain a third major tubulin subpopulation, composed of a non-tyrosinatable variant of tubulin that lacks a carboxy-terminal glutamyl-tyrosine group on its alpha-subunit (delta 2-tubulin). Here, the abundance of delta 2-tubulin in brain tissues, its distribution in developing rat cerebellum and in a variety of cell types have been examined and compared with that of total alpha-tubulin and of tyrosinated and detyrosinated tubulin. Delta 2-tubulin accounts for approximately 35% of brain tubulin. In rat cerebellum, delta 2-tubulin appears early during neuronal differentiation and is detected only in neuronal cells. This apparent neuronal specificity of delta 2-tubulin is confirmed by examination of its distribution in cerebellar cells in primary cultures. In such cultures, neuronal cells are brightly stained with anti-delta 2-tubulin antibody while glial cells are not. Delta 2-tubulin is apparently present in neuronal growth cones. As delta 2-tubulin, detyrosinated tubulin is enriched in neuronal cells, but in contrast with delta 2-tubulin, detyrosinated tubulin is not detectable in Purkinje cells and is apparently excluded from neuronal growth cones. In a variety of cell types such as cultured fibroblasts of primary culture of bovine adrenal cortical cells, delta 2-tubulin is confined to very stable structures such as centrosomes and primary cilia. Treatment of such cells with high doses of taxol leads to the appearance of delta 2-tubulin in microtubule bundles. Delta 2-tubulin also occurs in the paracrystalline bundles of protofilamentous tubulin formed after vinblastine treatment. Delta 2-tubulin is present in sea urchin sperm flagella and it appears in sea urchin embryo cilia during development. Thus, delta 2-tubulin is apparently a marker of very long-lived microtubules. It might represent the final stage of alpha-tubulin maturation in long-lived polymers.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells / chemistry
  • 3T3 Cells / ultrastructure
  • Adrenal Cortex / cytology
  • Adrenal Cortex / metabolism
  • Amino Acid Sequence
  • Animals
  • Cattle
  • Cells, Cultured
  • Centrosome / chemistry
  • Centrosome / ultrastructure
  • Cerebellum / embryology
  • Cerebellum / metabolism
  • Cilia / chemistry
  • Cilia / ultrastructure
  • Flagella / chemistry
  • Flagella / ultrastructure
  • Fluorescent Antibody Technique
  • Glial Fibrillary Acidic Protein / analysis
  • HeLa Cells / chemistry
  • HeLa Cells / ultrastructure
  • Humans
  • Male
  • Mice
  • Microtubule-Associated Proteins / analysis
  • Microtubules / chemistry*
  • Microtubules / drug effects
  • Molecular Sequence Data
  • Nerve Tissue Proteins / biosynthesis*
  • Nerve Tissue Proteins / genetics
  • Neurons / metabolism*
  • Neurons / ultrastructure
  • Paclitaxel / pharmacology
  • Protein Processing, Post-Translational
  • Purkinje Cells / metabolism
  • Rats
  • Sea Urchins / chemistry
  • Sea Urchins / embryology
  • Tubulin / biosynthesis*
  • Tubulin / genetics
  • Tyrosine / metabolism

Substances

  • Glial Fibrillary Acidic Protein
  • Microtubule-Associated Proteins
  • Nerve Tissue Proteins
  • Tubulin
  • Tyrosine
  • Paclitaxel