Viable clones of C2C12 myoblasts where both catalytic subunits of protein kinase CK2 had been knocked out by the CRISPR/Cas9 methodology have recently been generated, thus challenging the concept that CK2 is essential for cell viability. Here we present evidence that these cells are still endowed with a residual “CK2-like” activity that is able to phosphorylate Ser-13 of endogenous CDC37. Searching for a molecular entity accounting for such an activity we have identified a band running slightly ahead of CK2α′ on SDS-PAGE. This band is not detectable by in-gel casein kinase assay but it co-immuno-precipitates with the β-subunit being downregulated by specific CK2α′ targeting siRNA treatment. Its size and biochemical properties are consistent with those of CK2α′ mutants deleted upstream of Glu-15 generated during the knockout process. This mutant sheds light on the role of the CK2 N-terminal segment as a regulator of activity and stability. Comparable cytotoxic efficacy of two selective and structurally unrelated CK2 inhibitors support the view that survival of CK2α/α’−/− cells relies on this deleted form of CK2α′, whose discovery provides novel perspectives about the biological role of CK2.

A N-terminally deleted form of the CK2 alpha' catalytic subunit is sufficient to support cell viability

Borgo C.;D'Amore C.;Salvi M.
;
2020

Abstract

Viable clones of C2C12 myoblasts where both catalytic subunits of protein kinase CK2 had been knocked out by the CRISPR/Cas9 methodology have recently been generated, thus challenging the concept that CK2 is essential for cell viability. Here we present evidence that these cells are still endowed with a residual “CK2-like” activity that is able to phosphorylate Ser-13 of endogenous CDC37. Searching for a molecular entity accounting for such an activity we have identified a band running slightly ahead of CK2α′ on SDS-PAGE. This band is not detectable by in-gel casein kinase assay but it co-immuno-precipitates with the β-subunit being downregulated by specific CK2α′ targeting siRNA treatment. Its size and biochemical properties are consistent with those of CK2α′ mutants deleted upstream of Glu-15 generated during the knockout process. This mutant sheds light on the role of the CK2 N-terminal segment as a regulator of activity and stability. Comparable cytotoxic efficacy of two selective and structurally unrelated CK2 inhibitors support the view that survival of CK2α/α’−/− cells relies on this deleted form of CK2α′, whose discovery provides novel perspectives about the biological role of CK2.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/3349612
Citazioni
  • ???jsp.display-item.citation.pmc??? 6
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 8
social impact