Identification of a novel tubulin-destabilizing protein related to the chaperone cofactor E

J Cell Sci. 2005 Mar 15;118(Pt 6):1197-207. doi: 10.1242/jcs.01719. Epub 2005 Feb 22.

Abstract

Factors that regulate the microtubule cytoskeleton are critical in determining cell behavior. Here we describe the function of a novel protein that we term E-like based on its sequence similarity to the tubulin-specific chaperone cofactor E. We find that upon overexpression, E-like depolymerizes microtubules by committing tubulin to proteosomal degradation. Our data suggest that this function is direct and is based on the ability of E-like to disrupt the tubulin heterodimer in vitro. Suppression of E-like expression results in an increase in the number of stable microtubules and a tight clustering of endocellular membranes around the microtubule-organizing center, while the properties of dynamic microtubules are unaffected. These observations define E-like as a novel regulator of tubulin stability, and provide a link between tubulin turnover and vesicle transport.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Brain / metabolism
  • Caenorhabditis elegans
  • Cattle
  • Cell Membrane / metabolism
  • Cytoskeleton / metabolism
  • Cytosol / metabolism
  • DNA, Complementary / metabolism
  • Dimerization
  • Escherichia coli / metabolism
  • Expressed Sequence Tags
  • GTP Phosphohydrolases / chemistry
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Immunoblotting
  • Microscopy, Fluorescence
  • Microtubule-Associated Proteins / chemistry*
  • Microtubule-Associated Proteins / physiology*
  • Microtubules / metabolism
  • Molecular Chaperones / chemistry*
  • Molecular Chaperones / physiology
  • Molecular Sequence Data
  • Phylogeny
  • Plasmids / metabolism
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Protein Folding
  • RNA, Small Interfering / metabolism
  • Sequence Homology, Amino Acid
  • Tissue Distribution
  • Transfection
  • Tubulin / chemistry

Substances

  • DNA, Complementary
  • Microtubule-Associated Proteins
  • Molecular Chaperones
  • RNA, Small Interfering
  • TBCE protein, human
  • TBCEL protein, human
  • Tubulin
  • Green Fluorescent Proteins
  • Proteasome Endopeptidase Complex
  • GTP Phosphohydrolases