Evidence that the CD45 phosphatase regulates the activity of the phospholipase C in mouse T lymphocytes.
The importance of the tyrosine phosphatase CD45 in the regulation of lymphocyte activation was first demonstrated using antibodies against the extracellular domain of CD45 in functional assays. More recently it was reported that CD45-negative mutants were nonresponsive to stimulation through the T cell receptor-CD3 complex. We have studied the effect of CD45 cross-linking on the early signals induced by CD3 in mouse T cells. We show that CD45 cross-linking inhibits the increase in inositol phosphates and cytoplasmic Ca2+ induced by cross-linking of CD3. This indicates that CD45 is involved in the regulation of phospholipase C.
Marvel
J
J
Department of Biology, University College School of Medicine, London.
Rimon
G
G
Tatham
P
P
Cockcroft
S
S
D000818:Animals; D000943:Antigens, Differentiation / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D017252:CD3 Complex; D002118:Calcium / Q000502:physiology; D006649:Histocompatibility Antigens / Q000502:physiology*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D017493:Leukocyte Common Antigens; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051379:Mice; D008808:Mice, Inbred CBA; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D011940:Receptor Aggregation; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000201:enzymology*; D010738:Type C Phospholipases / Q000378:metabolism*
D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D006649:Histocompatibility Antigens; D011518:Proto-Oncogene Proteins; D011948:Receptors, Antigen, T-Cell; D015544:Inositol 1,4,5-Trisphosphate; D011505:Protein-Tyrosine Kinases; C494960:Fyn protein, mouse; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; D010749:Phosphoprotein Phosphatases; D017493:Leukocyte Common Antigens; D010738:Type C Phospholipases; D002118:Calcium