The regulation of B- and T-lymphocyte activation by the transmembrane protein tyrosine phosphatase CD45

1994 ◽  
Vol 6 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Matthew L. Thomas
Keyword(s):  
T Lymphocyte ◽  
Protein Tyrosine Phosphatase ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Lymphocyte Activation ◽  
Protein Tyrosine ◽  
T Lymphocyte Activation

Protein-tyrosine phosphatase activity of CD45 is activated by sequential phosphorylation by two kinases

1994 ◽  
Vol 14 (8) ◽  
pp. 5523-5532
Author(s):  
D R Stover ◽  
K A Walsh
Keyword(s):  
T Cell Activation ◽  
Protein Tyrosine Phosphatase ◽  
Time Course ◽  
Cell Activation ◽  
Regulatory Mechanism ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine

We describe a potential regulatory mechanism for the transmembrane protein-tyrosine phosphatase CD45. Phosphorylation on both tyrosine and serine residues in vitro results in an activation of CD45 specifically toward one artificial substrate but not another. The activation of these kinases appears to be order dependent, as it is enhanced when phosphorylation of tyrosine precedes that of serine but phosphorylation in the reverse order yields no activation. Any of four protein-tyrosine kinases tested, in combination with the protein-serine/threonine kinase, casein kinase II, was capable of mediating this activation in vitro. The time course of phosphorylation of CD45 in response to T-cell activation is consistent with the possibility that this regulatory mechanism is utilized in vivo.

scholarly journals Molecular Characterization of the Human Transmembrane Protein-tyrosine Phosphatase δ

1995 ◽  
Vol 270 (12) ◽  
pp. 6722-6728 ◽  
Author(s):  
Rafael Pulido ◽  
Neil X. Krueger ◽  
Carles Serra-Pagès ◽  
Haruo Saito ◽  
Michel Streuli
Keyword(s):  
Molecular Characterization ◽  
Protein Tyrosine Phosphatase ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Protein Tyrosine

scholarly journals CD8+ T-cell clones deficient in the expression of the CD45 protein tyrosine phosphatase have impaired responses to T-cell receptor stimuli.

1991 ◽  
Vol 11 (9) ◽  
pp. 4415-4422 ◽  
Author(s):  
C T Weaver ◽  
J T Pingel ◽  
J O Nelson ◽  
M L Thomas
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Protein Tyrosine Phosphatase ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Cell Receptor ◽  
T Cell Clones ◽  
Protein Tyrosine ◽  
Receptor Signalling ◽  
Cell Clones

CD45 is a high-molecular-weight transmembrane protein tyrosine phosphatase expressed only by nucleated cells of hematopoietic origin. To examine function, mouse CD8+ cytolytic T-cell clones were derived that had a specific defect in the expression of CD45. Northern (RNA) blot analysis indicates that the CD45 deficiency is due to either a transcriptional defect or mRNA instability. The CD45-deficient cells were greatly diminished in their ability to respond to antigen. All functional parameters of T-cell receptor signalling analyzed (cytolysis of targets, proliferation, and cytokine production) were markedly diminished. A CD45+ revertant was isolated, and the ability to respond to antigen was restored. These results support a central and immediate role for this transmembrane protein tyrosine phosphatase in T-cell receptor signalling.

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