• Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

Syk-dependent phosphorylation of microtubules in activated B-lymphocytes.

Syk is a protein-tyrosine kinase that is essential for B-lymphocyte development and B-cell signaling. Syk phosphorylates tubulin on tyrosine both in vitro and in intact lymphocytes. Here we show that (alpha)-tubulin present within the cytoskeletal microtubule network was phosphorylated in a Syk-dependent manner following the activation of B-cells by engagement of the B-cell antigen receptor or by treatment with the phosphotyrosine phosphatase inhibitor, pervanadate. Immunofluorescence staining of microtubule cytoskeletons and western blotting studies with antibodies to phosphotyrosine confirmed the phosphorylation of polymerized tubulin in Syk-expressing, but not Syk-deficient, cells. At low concentrations of pervanadate, centrosomes appeared to be preferentially tyrosine-phosphorylated. Tubulin phosphorylated to a high stoichiometry on tyrosine assembled into microtubules in vitro, and preassembled microtubules were also phosphorylated by Syk kinase in vitro. Thus, Syk has the capacity to interact with microtubule networks within the B-lymphocyte and catalyzes the phosphorylation of the (alpha)-tubulin subunit. Syk-dependent phosphorylation of microtubules may affect the ability of the microtubule cytoskeleton to serve as a platform upon which signaling complexes are assembled.

Pubmed ID: 10862713

Authors

  • Faruki S
  • Geahlen RL
  • Asai DJ

Journal

Journal of cell science

Publication Data

July 18, 2000

Associated Grants

  • Agency: NCI NIH HHS, Id: CA37372

Mesh Terms

  • Animals
  • Antibodies, Anti-Idiotypic
  • B-Lymphocytes
  • Biopolymers
  • Cell Line
  • Centrosome
  • Chickens
  • Cytoskeleton
  • Enzyme Inhibitors
  • Enzyme Precursors
  • Gene Deletion
  • Intracellular Signaling Peptides and Proteins
  • Lymphocyte Activation
  • Microtubules
  • Phosphorylation
  • Phosphotyrosine
  • Protein Tyrosine Phosphatases
  • Protein-Tyrosine Kinases
  • Signal Transduction
  • Tubulin
  • Vanadates