Cellular regulators of protein kinase CK2

Abstract

Protein phosphorylation is a key regulatory post-translational modification and is involved in the control of many cellular processes. Protein kinase CK2, formerly known as casein kinase II, which is a ubiquitous and highly conserved protein serine/threonine kinase, plays a central role in the control of a variety of pathways in cell proliferation, transformation, apoptosis and senescence. An understanding of the regulation of such a central protein kinase would greatly help our comprehension of the regulation of many pathways in cellular regulation. A number of reviews have addressed the detection, the development, and the characterization of inhibitors of CK2. The present review focuses on possible natural regulators of CK2, i.e. proteins and other cellular factors that bind to CK2 and thereby regulate its activity.

Drosophila Mbm Is a Nucleolar Myc and Casein Kinase 2 Target Required for Ribosome Biogenesis and Cell Growth of Central Brain Neuroblasts

“…CK2 is often considered a constitutively active kinase which is not regulated by second messenger signaling cascades. However, there is increasing evidence for regulation of CK2 at the levels of the holoenzyme, the dynamics of localization of individual subunits under different conditions, and interactions with small molecules such as polyamines (70,71). Overexpression of ornithine decarboxylase, the rate-limiting enzyme in polyamine biosynthesis and a known Myc target gene, increases CK2 phosphorylation activity toward nucleolar B23 in mouse keratinocytes (72).…”

Casein kinase 2 (CK2) phosphorylates the deubiquitylase OTUB1 at Ser 16 to trigger its nuclear localization

“…Other global phosphoproteomic studies have also noted Ser 16 and Ser 18 on OTUB1 as phospho-modified residues, although the kinase(s) involved and the roles of these phosphorylation events remained to be defined (18)(19)(20)(21). The residues surrounding Ser 16 of OTUB1, GSDSEGVN, with acidic residues at +1 and +3, make it an optimal site for phosphorylation by protein kinase CK2 (22)(23)(24). CK2 (derived from the misnomer casein kinase 2) is a ubiquitously expressed and highly pleiotropic protein kinase.…”

Synthesis and biological actions of diphosphoinositol phosphates (inositol pyrophosphates), regulators of cell homeostasis

“…While it remains intriguing that a PTM should occur nonenzymatic, a protein kinase, namely CKII still is involved. CKII is a ubiquitous serine/threonine protein kinase involved in several cellular processes, but to date the regulation of CKII is not really understood (for a review see Montenarh , 2010 ). Notably, CKII alone (Solyakov et al , 2004 ) and CKII in a complex with Nopp140 (a nucleolar protein) are upregulated by InsP 6 binding (Kim et al , 2006 ;Lee et al , 2008a ).…”