Role of the kinase activation loop on protein kinase C θ activity and intracellular localisation

FEBS Letters

Pontremoli, Sandro²  Ledda, Sabina²  Passalacqua, Mario²  Patrone, Mauro¹  Sparatore, Bianca²  Gaggero, Deborah²  Melloni, Edon²  Pedrazzi, Marco² 

[1] Department of Advanced Science and Technology, University of Eastern Piedmont ‘Amedeo Avogadro’, Corso Borsalino 54, 15100 Alessandria, Italy;Department of Experimental Medicine, Biochemistry Section, University of Genoa, Viale Benedetto XV, 16132 Genoa, Italy

关键词: Golgi complex;    Erythroleukemia cell;    Protein kinase C θ phosphorylation;    Thr538→Ala protein kinase Cθ;    Thr538→Glu protein kinase Cθ;    PKC;    protein kinase C;    MEL;    murine erythroleukaemia;    PMA;    phorbol myristate acetate;    MBP;    myelin basic protein;    WGA;    wheat germ agglutinin;    PP;    PKCθ pseudosubstrate peptide;   

DOI  :  10.1016/S0014-5793(03)01073-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Multiple protein kinase C (PKC) θ species, identified in an erythroleukaemia cell line, have been characterised in terms of their molecular properties and intracellular distribution. PKCθs localised in the detergent-soluble cell fraction have an M _r of 76 kDa (θ-76) and contain Thr⁵³⁸ or pThr⁵³⁸ in the kinase activation loop. In contrast, PKCθs localised in the Golgi complex have an M _r of 85 kDa (θ-85) and, although unphosphorylated at Thr⁵³⁸, are catalytically active. Strikingly, only θ-76 species which are unphosphorylated at Thr⁵³⁸ can undergo autocatalytic conversion to θ-85. Moreover, a Thr⁵³⁸→Ala PKCθ mutant is constitutively localised in the Golgi complex, confirming that changes in the phosphorylation state of this residue play a pivotal role in the overall control of catalytic properties and localisation of this kinase.

【 授权许可】

Unknown