Protein Kinase CK2 Subunits Differentially Perturb the Adhesion and Migration of GN11 Cells: A Model of Immature Migrating Neurons

Abstract

Protein kinase CK2 (CK2) is a highly conserved and ubiquitous kinase is involved in crucial biological processes, including proliferation, migration, and differentiation. CK2 holoenzyme is a tetramer composed by two catalytically active (α/α’) and two regulatory (β) subunits and exerts its function on a broad range of targets. In the brain, it regulates different steps of neurodevelopment, such as neural differentiation, neuritogenesis, and synaptic plasticity. Interestingly, CK2 mutations have been recently linked to neurodevelopmental disorders; however, the functional requirements of the individual CK2 subunits in neurodevelopment have not been yet investigated. Here, we disclose the role of CK2 on the migration and adhesion properties of GN11 cells, an established model of mouse immortalized neurons, by different in vitro experimental approaches. Specifically, the cellular requirement of this kinase has been assessed pharmacologically and genetically by exploiting CK2 inhibitors and by generating subunit-specific CK2 knockout GN11 cells (with a CRISPR/Cas9-based approach). We show that CK2α’ subunit has a primary role in increasing cell adhesion and reducing migration properties of GN11 cells by activating the Akt-GSK3β axis, whereas CK2α subunit is dispensable. Further, the knockout of the CK2β regulatory subunits counteracts cell migration, inducing dramatic alterations in the cytoskeleton not observed in CK2α’ knockout cells. Collectively taken, our data support the view that the individual subunits of CK2 play different roles in cell migration and adhesion properties of GN11 cells, supporting independent roles of the different subunits in these processes.

Anti-Müllerian Hormone, Growth Hormone, and Insulin-Like Growth Factor 1 Modulate the Migratory and Secretory Patterns of GnRH Neurons

“…For cytoskeleton labeling, GN11 cells were seeded at a density of 5 × 10 3 cells/well in a 24-multiwell plate, two days after they were treated for 60/120 min with the different hormones and fixed with 4% paraformaldehyde-PBS for 15 min at RT and immunostained as previously described [ 35 ]. Briefly, fixed cells were then incubated with an anti-alpha-tubulin primary antibody at room temperature for 2 h, followed by an anti-mouse 488-conjugated secondary antibody at room temperature for 2 h. To detect F-actin, cells were treated with phalloidin-TRITC (1:400, in PBS) for 30 min at 37 °C before mounting with Mowiol.…”

Role of CK2 inhibitor CX-4945 in anti-cancer combination therapy – potential clinical relevance

“…In addition, CX-4945 has been found to strongly inhibit cell migration and differentiation [3]. These effects are strictly related to a rapid inhibition of CK2, since the reduction in phosphorylation of the main substrates of the kinase occurs within a few hours after CX-4945 administration [3,33,36]. Data obtained through a recent phosphoproteomic analysis performed in mitotic HeLa cells confirmed that CK2 is the main kinase target of CX-4945.…”

“…It is widely acknowledged that the Ser/Thr protein kinase CK2, a tetrameric holoenzyme composed of two catalytic α (or α') and a dimer of regulatory β subunits, is involved in the regulation of a plethora of biological processes and basal cellular functions, including growth, proliferation and differentiation, transcription and translation, glucose uptake, adhesion and migration [1][2][3][4][5][6][7]. This pleiotropy relays on the fact that CK2 is a ubiquitously expressed and constitutively active protein kinase, with hundreds of substrates widely distributed in most of the subcellular compartments [8,9].…”

“…When administered in cells, CX-4945 has been found to show an extensive anti-proliferative activity, i.e., to promote cell cycle arrest, and to induce caspase activity and apoptosis in various cancer cell lines [10,11,16]. In addition, CX-4945 has been found to strongly inhibit cell migration and differentiation [3]. These effects are strictly related to a rapid inhibition of CK2, since the reduction in phosphorylation of the main substrates of the kinase occurs within a few hours after CX-4945 administration [3,33,36].…”

Contribution of the CK2 Catalytic Isoforms α and α’ to the Glycolytic Phenotype of Tumor Cells

“…In contrast, specific functions of α respect to α’ appear to play a role in the regulation of metabolic rewiring. CK2 isoform-specific substrates/partners/functions have been already reported [ 11 , 31 , 39 , 40 , 41 ]; further studies will be necessary to assess their effective implication in cancer cell metabolism and to identify novel targets and mechanisms that might be implicated. However, it is also important to notice that, as previously observed in other cell lines [ 31 ], the KOα clones display a reduction of the β CK2 regulatory subunit, which is not (or only marginally) appreciable in KOα’ cells ( Figure 1 ).…”