Human T lymphocyte activation induces tyrosine phosphorylation of alpha-tubulin and its association with the SH2 domain of the p59fyn protein tyrosine kinase.
A glutathione-S-transferase-src-homology domain 2 (GST-SH2) fusion protein was employed to identify molecules interacting with the protein tyrosine kinase p59fyn. Among several proteins which bound to the fyn SH2 domain in lysates of human Jurkat T lymphocytes, alpha- and beta-tubulin were identified by N-terminal sequencing. Further analysis established that alpha-tubulin exists as a tyrosine-phosphorylated protein in Jurkat cells, where it interacts with p59fyn, but not with p56lck. By contrast, in untransformed resting human T lymphocytes alpha-tubulin is not detectable as a tyrosine phosphorylated protein. However, following T cell activation, it becomes rapidly phosphorylated on tyrosine residues and subsequently associates with the SH2 domain of fyn. Interestingly, constitutively tyrosine-phosphorylated alpha-tubulin that is able to interact with the fyn-SH2 domain is expressed in peripheral blood T lymphoblasts isolated from leukemic patients in the absence of external stimulation.
Marie-Cardine
A
A
Department of Applied Immunology, German Cancer Research Center, Heidelberg, Germany.
Kirchgessner
H
H
Eckerskorn
C
C
Meuer
S C
SC
Schraven
B
B
D000595:Amino Acid Sequence; D006801:Humans; D015458:Leukemia, T-Cell / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D016399:Lymphoma, T-Cell; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000276:immunology / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000276:immunology / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology; D014404:Tubulin / Q000276:immunology / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000494:pharmacology; D014638:Vanadates / Q000494:pharmacology; D018909:src Homology Domains / Q000276:immunology*
D011518:Proto-Oncogene Proteins; D014404:Tubulin; C076715:pervanadate; D014638:Vanadates; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; D051076:Proto-Oncogene Proteins c-fyn; D010744:Phosphoric Monoester Hydrolases