Ordered phosphorylation of p42mapk by MAP kinase kinase

FEBS Letters

Dent, Paul¹  Haystead, Clare M.M.¹  Wu, Jie¹  Haystead, Timothy A.J.¹  Sturgill, Thomas W.¹ 

[1] Department of Pharmacology, Health Sciences Center, Box 448, University of Virginia, Charlottesville, VA 22908, USA

关键词: Recombinant p42mapk;    Skeletal muscle;    MAP kinase kinase;    MAP kinase;    mitogen-activated protein kinase;    RT;    retention time;    p42mapk;    42 kDa MAP kinase;    PP-2A;    protein phosphatase 2A;    PTPase;    protein tyrosine phosphatase;    MBP;    myelin basic protein;   

DOI  :  10.1016/0014-5793(92)80828-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Preparation of milligram amounts of [³²P]p42^mapk, phosphorylaled at Tyr¹⁸⁵ or diphosphorylated at Tyr¹⁸⁵/Thr¹⁸³, for use as specific protein phosphatase substrates is described. Tyr- but not Thr-phosphorylated p42^mapk, accumulates when ATP is limiting. Furthermore, Tyr¹⁸⁵-phosphorylated p42^mapk exhibits an apparent 10-fold decrease in apparent K _m (46.6 ± 6.6 nM) for MAP kinase kinase compared to that for the dephospho form (∼476 nM). We conclude that Tyr¹⁸⁵ precedes Tyr¹⁸⁵ phosphorylation, and that this is prerequisite, dramatically increasing the affinity of p42^mapk for MAP kinase kinase.

【 授权许可】

Unknown