ACTIVATION OF HUMAN THYMOCYTES INDUCES THE PHOSPHORYLATION OF PROTEIN-TYROSINE-PHOSPHATASE 1C

被引:0
作者
TRACHMAN, JD
HUANG, J
REEM, GH
机构
[1] NYU,MED CTR,DEPT PHARMACOL,NEW YORK,NY 10016
[2] NYU,MED CTR,KAPLAN CANC CTR,NEW YORK,NY 10016
来源
COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES | 1995年 / 318卷 / 03期
关键词
PROTEIN TYROSINE PHOSPHATASE; HUMAN THYMOCYTES; SIGNAL TRANSDUCTION; PHOSPHORYLATION;
D O I
暂无
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Phosphorylation of docking proteins is essential for signal transduction. In this report we provide evidence that activation of human thymocytes in culture induces the phosphorylation of the protein tyrosine phosphatase 1C (PTP 1C). Thymocytes were activated with Con A, PMA or Con A+PMA. The enzyme is phosphorylated on its serine and threonine residues. Phosphorylation occurs within 5 min and lasts for 24 h. PTP 1C is phosphorylated by PKC in vivo and in vitro; however, phosphopeptide mapping suggests that in addition to PKC other kinases phosphorylate the enzyme. On the maps of tryptic digests of cultured thymocytes more radiolabeled phosphopeptides are visualized than an the maps of digests of PTP 1C phosphorylated with partially purified PKC alpha or beta. Phosphorylation of PTP 1C decreases its activity, whereas dephosphorylation increases its activity, suggesting that phosphorylation of PTP 1C takes part in the regulation of signal transduction.
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页码:367 / 374
页数:8
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