P56lck A lymphocyte specific protein tyrosine kinase: activation, regulation and signal transduction.
p56lck, a src family protein tyrosine kinase interacts with several T cell receptors, like: CD4, CD8, CD2 and the beta-chain of the IL2, thereby receptors devoid of kinase activity may transduce signals via tyr phosphorylation. Tyr 192 and ser 194, located in the SH2 domain of p56lck is phosphorylated upon CD3 triggering, which can change interactions of tyr-P proteins with this SH2 domain. Upon activation through the CD2 or the CD45 receptors the kinase activity of p56lck is temporarily increased. By immunofluorescent and confocal microscopy we observed that a significant proportion of p56lck and CD2 receptors are localized in endosomal vesicles after stimulation. By Western blot we showed a parallel recruitment of the PTK p70-ZAP in this vesicles. The role of p56lck away from the plasma membrane localized in vesicles is under study.
Fischer
S
S
Institut Cochin de Genetique Moleculaire-ICGM- U363 INSERM, Paris, France.
Marie-Cardine
A
A
Ramos-Morales
F
F
Bougeret
C
C
Soula
M
M
Maridonneau-Parini
I
I
Benarous
R
R
D018801:CD2 Antigens / Q000378:metabolism; D002460:Cell Line; D011992:Endosomes / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D017493:Leukocyte Common Antigens / Q000378:metabolism; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000201:enzymology; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology
D018801:CD2 Antigens; D013438:Sulfhydryl Compounds; D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D017493:Leukocyte Common Antigens