Determination of phosphotyrosine phosphatase (PTPase) activity in normal and transformed cells

1993 ◽  
Vol 125 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Joachim Kremerskothen ◽  
Angelika Barnekow
Keyword(s):  
Transformed Cells ◽  
Phosphotyrosine Phosphatase ◽  
Ptpase Activity

scholarly journals Tyrosine phosphorylation of CD45 phosphotyrosine phosphatase by p50csk kinase creates a binding site for p56lck tyrosine kinase and activates the phosphatase.

1994 ◽  
Vol 14 (2) ◽  
pp. 1308-1321 ◽  
Author(s):  
M Autero ◽  
J Saharinen ◽  
T Pessa-Morikawa ◽  
M Soula-Rothhut ◽  
C Oetken ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Lymphocyte Activation ◽  
Sh2 Domain ◽  
Protein Tyrosine Kinases ◽  
Phosphotyrosine Phosphatase ◽  
Intact Cells ◽  
Tyrosine Residues ◽  
Family Protein ◽  
Ptpase Activity

Src family protein tyrosine kinases (PTKs) play an essential role in antigen receptor-initiated lymphocyte activation. Their activity is largely regulated by a negative regulatory tyrosine which is a substrate for the activating action of the CD45 phosphotyrosine phosphatase (PTPase) or, conversely, the suppressing action of the cytosolic p50csk PTK. Here we report that CD45 was phosphorylated by p50csk on two tyrosine residues, one of them identified as Tyr-1193. This residue was not phosphorylated by T-cell PTKs p56lck and p59fyn. Tyr-1193 was phosphorylated in intact T cells, and phosphorylation increased upon treatment with PTPase inhibitors, indicating that this tyrosine is a target for a constitutively active PTK. Cotransfection of CD45 and csk into COS-1 cells caused tyrosine phosphorylation of CD45 in the intact cells. Tyrosine-phosphorylated CD45 bound p56lck through the SH2 domain of the kinase. Finally, p50csk-mediated phosphorylation of CD45 caused a severalfold increase in its PTPase activity. Our results show that direct tyrosine phosphorylation of CD45 can affect its activity and association with Src family PTKs and that this phosphorylation could be mediated by p50csk. If this is also true in the intact cells, it adds a new dimension to the physiological function of p50csk in T lymphocytes.

Altered basal and insulin-stimulated phosphotyrosine phosphatase (PTPase) activity in skeletal muscle from NIDDM patients compared with control subjects

Diabetologia ◽  
1996 ◽  
Vol 39 (10) ◽  
pp. 1208-1214 ◽  
Author(s):  
D. Worm ◽  
J. Vinten ◽  
P. Staehr ◽  
J. E. Henriksen ◽  
A. Handberg ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Phosphotyrosine Phosphatase ◽  
Control Subjects ◽  
Niddm Patients ◽  
Ptpase Activity

Determination of the h-protein in transformable and transformed cells in culture

Biochemistry ◽  
1972 ◽  
Vol 11 (11) ◽  
pp. 2116-2124 ◽  
Author(s):  
Toshio Kuroki ◽  
Charles Heidelberger
Keyword(s):  
Transformed Cells ◽  
Cells In Culture ◽  
H Protein

scholarly journals Tyrosine kinase and phosphotyrosine phosphatase activity in human promyelocytic leukemia cells and human polymorphonuclear leukocytes

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 356-362
Author(s):  
AS Kraft ◽  
RL Berkow
Keyword(s):  
Tyrosine Kinase ◽  
Phosphatase Activity ◽  
Polymorphonuclear Leukocytes ◽  
Phorbol Esters ◽  
Promyelocytic Leukemia ◽  
Leukemia Cells ◽  
Phosphotyrosine Phosphatase ◽  
Significant Drop ◽  
Human Polymorphonuclear Leukocytes ◽  
Ptpase Activity

Although an increase in protein phosphorylation on tyrosine was first noted as a result of cell transformation or the application of growth factors to cells, recent reports have shown high levels of tyrosine kinases in nondividing tissues. For that reason, we have investigated whether normal human polymorphonuclear leukocytes (PMN) contain tyrosine kinase and phosphatase activity. Using a copolymer of glutamine: tyrosine as a substrate for the phosphotransferase reaction, we have demonstrated that PMN contain a cytosolic tyrosine kinase activity that elutes as a single peak from Sephacryl S-200 chromatography and has a molecular weight of 70 kilodaltons. Human promyelocytic leukemia cells (HL-60), contain a similar activity (as demonstrated by column chromatography), with only 25% of the activity found in PMN. This cytosolic tyrosine kinase can phosphorylate angiotensin II and a fragment of the src protein containing tyrosine 416, which suggests a similar substrate specificity to other tyrosine- phosphorylating protein kinases. In addition, we have demonstrated that PMN have double the amount of phosphotyrosine phosphatase (PTPase) activity of that found in HL-60 cells. This enzyme has a Km of 0.932 mmol/L and a Vmax of 0.355 mumol inorganic phosphate released/mg protein/min, which is similar to other cellular PTPase. Activation of PMN with f-Met-Leu-Phe and phorbol esters causes a slight but statistically significant drop in PMN PTPase activity. These results suggest that terminally differentiated myeloid cells have high tyrosine kinase and phosphatase activity, which may play a role in stimulus response coupling in the mature PMN.

Quantitative cytofluorimetric determination of cell membrane-associated large tumor antigen on SV40-transformed cells

Cytometry ◽  
1995 ◽  
Vol 20 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Ralf D. Hess ◽  
Markus Kuther ◽  
Christel Haessler ◽  
Susanne Paetzold ◽  
Dietmar G. Braun ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Tumor Antigen ◽  
Transformed Cells ◽  
Large Tumor ◽  
Large Tumor Antigen

scholarly journals TSH-induced differentiated functions correlate with enhancement of phosphotyrosine phosphatase activity in thyroid cells. Effect of phorbol 12-myristate 13-acetate

2001 ◽  
Vol 169 (3) ◽  
pp. 603-611 ◽  
Author(s):  
E Petitfrere ◽  
E Huet ◽  
H Sartelet ◽  
L Martiny ◽  
O Legue ◽  
...  
Keyword(s):  
Phosphatase Activity ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Phosphotyrosine Phosphatase ◽  
Thyroid Cells ◽  
Kinase C ◽  
Gf 109203X ◽  
Dose Dependent ◽  
Ptpase Activity

TSH-treated pig thyroid cells reorganize into follicle-like structures and exhibit differentiated functions. TSH also induces a phosphotyrosine phosphatase (PTPase) activity evaluated by phosphorylated substrate hydrolysis. Incubation of thyrocytes with various concentrations of 8-bromo-cyclic AMP or forskolin induces an increase of PTPase activity in a dose-dependent manner. During the culture period, adenylyl cyclase sensitivity, protein binding iodine and PTPase activity progressively increase from the first to the fourth day of the culture. Chronic treatment with phorbol 12-myristate 13-acetate (PMA) significantly inhibits PTPase activity during the first 24 h following PMA addition. GF 109203X, a specific inhibitor of protein kinase C, abolishes the inhibitory effect of PMA. Electrophoresis of membrane extracts allowed us to demonstrate a phosphatase activity at 111 kDa (p111). Vanadate inhibits this activity, indicating that p111 is a PTPase. This p111 is significantly reduced in PMA-treated cells. These data suggest that PTPase activity evidenced at 111 kDa is correlated with a differentiated state of primary cultured pig thyroid cells induced by TSH.

scholarly journals Tyrosine kinase and phosphotyrosine phosphatase activity in human promyelocytic leukemia cells and human polymorphonuclear leukocytes

Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 356-362 ◽  
Author(s):  
AS Kraft ◽  
RL Berkow
Keyword(s):  
Tyrosine Kinase ◽  
Phosphatase Activity ◽  
Polymorphonuclear Leukocytes ◽  
Phorbol Esters ◽  
Promyelocytic Leukemia ◽  
Leukemia Cells ◽  
Phosphotyrosine Phosphatase ◽  
Significant Drop ◽  
Human Polymorphonuclear Leukocytes ◽  
Ptpase Activity

Abstract Although an increase in protein phosphorylation on tyrosine was first noted as a result of cell transformation or the application of growth factors to cells, recent reports have shown high levels of tyrosine kinases in nondividing tissues. For that reason, we have investigated whether normal human polymorphonuclear leukocytes (PMN) contain tyrosine kinase and phosphatase activity. Using a copolymer of glutamine: tyrosine as a substrate for the phosphotransferase reaction, we have demonstrated that PMN contain a cytosolic tyrosine kinase activity that elutes as a single peak from Sephacryl S-200 chromatography and has a molecular weight of 70 kilodaltons. Human promyelocytic leukemia cells (HL-60), contain a similar activity (as demonstrated by column chromatography), with only 25% of the activity found in PMN. This cytosolic tyrosine kinase can phosphorylate angiotensin II and a fragment of the src protein containing tyrosine 416, which suggests a similar substrate specificity to other tyrosine- phosphorylating protein kinases. In addition, we have demonstrated that PMN have double the amount of phosphotyrosine phosphatase (PTPase) activity of that found in HL-60 cells. This enzyme has a Km of 0.932 mmol/L and a Vmax of 0.355 mumol inorganic phosphate released/mg protein/min, which is similar to other cellular PTPase. Activation of PMN with f-Met-Leu-Phe and phorbol esters causes a slight but statistically significant drop in PMN PTPase activity. These results suggest that terminally differentiated myeloid cells have high tyrosine kinase and phosphatase activity, which may play a role in stimulus response coupling in the mature PMN.

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