TY - JOUR
T1 - Phorbol 12-myristate 13-acetic acid inhibits PTP1B activity in human mesangial cells A possible mechanism of enhanced tyrosine phosphorylation
AU - Kiyomoto, Hideyasu
AU - Fouqueray, Bruno
AU - Abboud, Hanna E.
AU - Choudhury, Goutam Ghosh
N1 - Funding Information:
Acknowledgements." This study was supported by AHA-Texas affiliate and NIH Grant DK 43988. B.F. was supported by a grant from Foundation Pour La Recherche Medicale, France. The authors acknowledge Kathleen Woodruff and Sergio Garcia for technical help.
PY - 1994/10/17
Y1 - 1994/10/17
N2 - Activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetic acid (PMA) stimulates DNA synthesis in human glomerular mesangial cells. Incubation of these cells with PMA stimulates the tyrosine phosphorylation of a set of proteins ranging from 110 to 39 kDa with different time kinetics. PMA inhibits total protein tyrosine phosphatase (PTPase) activity in these cells. Immunoprecipitation of PTP1B, an intracytoplasmic tyrosine phosphatase, with subsequent assay of the immunobeads for PTPase shows a significant inhibition of its activity in PMA-treated cells. Immunoblot analysis of mesangial cell lysates using the same antibody revealed that PMA does not affect the level of this 50 kDa PTP1B protein. These data indicate that inhibition of total PTPase, and specifically PTP1B, activity may provide a mechanism for stimulation of tyrosine phosphorylation by PMA in these cells and thereby contribute to its mitogenic effect.
AB - Activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetic acid (PMA) stimulates DNA synthesis in human glomerular mesangial cells. Incubation of these cells with PMA stimulates the tyrosine phosphorylation of a set of proteins ranging from 110 to 39 kDa with different time kinetics. PMA inhibits total protein tyrosine phosphatase (PTPase) activity in these cells. Immunoprecipitation of PTP1B, an intracytoplasmic tyrosine phosphatase, with subsequent assay of the immunobeads for PTPase shows a significant inhibition of its activity in PMA-treated cells. Immunoblot analysis of mesangial cell lysates using the same antibody revealed that PMA does not affect the level of this 50 kDa PTP1B protein. These data indicate that inhibition of total PTPase, and specifically PTP1B, activity may provide a mechanism for stimulation of tyrosine phosphorylation by PMA in these cells and thereby contribute to its mitogenic effect.
KW - PTP1B
KW - Phorbol ester
KW - Protein tyrosine phosphatase
KW - Tyrosine phosphorylation
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U2 - 10.1016/0014-5793(94)01039-0
DO - 10.1016/0014-5793(94)01039-0
M3 - Article
C2 - 7523196
AN - SCOPUS:0027948285
VL - 353
SP - 217
EP - 220
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 2
ER -