CK2 is a pleiotropic and constitutively active serine/threonine protein kinase composed of two catalytic (α and/or α′) and two regulatory β-subunits, whose mechanism of modulation is still obscure. Here we show that CK2 α/α′ subunits undergo intermolecular (trans) tyrosine-autophosphorylation, which is dependent on intrinsic catalytic activity and is suppressed by the individual mutation of Tyr182, a crucial residue of the activation loop, to phenylalanine. At variance with serine-autophosphorylation, tyrosine-autophosphorylation of CK2α is reversed by ADP and GDP and is counteracted by the β-subunit and by a peptide reproducing the activation loop of CK2α/α′ (amino acids 175–201). These results disclose new perspectives about the mode of regulation of CK2 catalytic subunits.
Autocatalytic tyrosine-phosphorylation of protein kinase CK2 α and α′ subunits: implication of Tyr182
- Views Icon Views
- Share Icon Share
Arianna DONELLA-DEANA, Luca CESARO, Stefania SARNO, Anna Maria BRUNATI, Maria RUZZENE, Lorenzo A. PINNA; Autocatalytic tyrosine-phosphorylation of protein kinase CK2 α and α′ subunits: implication of Tyr182. Biochem J 15 July 2001; 357 (2): 563–567. doi: https://doi.org/10.1042/bj3570563
Download citation file: