Protein kinase CK2 from two higher eukaryotes of economical importance, the mussel Mytilus galloprovincialis and the medfly Ceratitis capitata

Abstract

Protein kinase CK2 is a highly conserved Ser/Thr protein kinase involved in cell cycle control, transcription, signal transduction and cell proliferation. It is upregulated in several diseases and by oxidative stress. CK2 is generally composed of two catalytic subunits and two regulatory subunits and utilizes either ATP or GTP as a phosphate donor. CK2 was isolated from the sea mussel Mytilus galloprovincialis, a biomarker of marine pollution, and the Mediterranean fly Ceratitis capitata, an insect capable of wreaking extensive damage to a wide range of fruit crops with great economical importance. The catalytic CK2α and regulatory CK2β subunits of M. galloprovincialis and C. capitata show similar properties. The mussel and fly catalytic subunits and holoenzymes were capable of phosphorylating the recombinant ribosomal stalk P1 protein, implying functional conservation. They also demonstrate the characteristics of a typical CK2: use of ATP and GTP as phosphate donors, inhibition by known modulators of CK2 activity (like benzotriazole derivatives and heparin), and stimulation by polycations. Both organisms seem to be ideal models for the analysis of CK2 in the control of gene expression in response to cellular stress. © 2012 Versita Warsaw and Springer-Verlag Wien.