Phosphotyrosine as a specificity determinant for casein kinase‐2, a growth related Ser/Thr‐specific protein kinase

FEBS Letters

Pinna, Lorenzo A.²  Reynolds, Eric C.¹  Meggio, Flavio²  Perich, John W.¹ 

[1] Biochemistry and Molecular Biology Unit, School of Dental Science, The University of Melbourne, Melbourne, Australia;Dipartimento di Chimica Biologica dell'Università di Padova, Italy

关键词: Protein kinase;    Casein kinase-2;    Phosphopeptide;    Phosphotyrosine (as specificity determinant);    CK-1;    casein kinase-1;    GSK-3;    glycogen synthase kinase-3;    CK-2;    casein kinase-2;    Sp or SerP;    Phosphoserine;    Tp or ThrP;    phosphothreonine;    Yp or TyrP;    phosphotyrosine;   

DOI  :  10.1016/0014-5793(91)80174-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The motif Ser-Ser-Ser-Glu-Glu is readily phosphorylated by casein kinase-2 (CK-2), a growth-related protein kinase whose consensus sequence is Ser(Thr)-Xaa-Xaa-Glu(Asp) [(1990) Biochim. Biophys. Acta. 1054, 267–283]. Here we show that phosphotyrosine can replace carboxylic acids as specificity determinant for CK-2 phosphorylation, the phosphotyrosyl peptide Ser-Ser-Ser-TyrP-TyrP actually being a substrate more efficient than Ser-Ser-Ser-Glu-Glu itself both in terms of K _m (0.69 vs 2.43 mM) and V???. Prior dephosphorylation of phosphotyrosine entirely prevents the subsequent phosphorylation of serine by CK-2. While Ser-Ser-Ser-TyrP-TyrP is better than Ser-Ser-Ser-SerP-SerP, which in turn is better than Ser-Ser-Ser-Glu-Glu, Ser-Ser-Ser-ThrP-ThrP is a less efficient substrate than Ser-Ser-Ser-Glu-Glu. Thus the order of efficiency of phosphoamino acids as specificity determinants for CK-2 appears to be TyrP>SerP>ThrP.

【 授权许可】

Unknown