CK2 functionally interacts with AKT/PKB to promote the β-catenin-dependent expression of survivin and enhance cell survival

Mol Cell Biochem. 2011 Oct;356(1-2):127-32. doi: 10.1007/s11010-011-0965-4. Epub 2011 Jul 7.

Abstract

β-Catenin is crucial in the canonical Wnt signaling pathway. This pathway is up-regulated by CK2 which is associated with an enhanced expression of the antiapoptotic protein survivin, although the underlying molecular mechanism is unknown. AKT/PKB kinase phosphorylates and promotes β-catenin transcriptional activity, whereas CK2 hyperactivates AKT by phosphorylation at Ser129; however, the role of this phosphorylation on β-catenin transcriptional activity and cell survival is unclear. We studied in HEK-293T cells, the effect of CK2-dependent hyperactivation of AKT on cell viability, as well as analyzed β-catenin subcellular localization and transcriptional activity and survivin expression. CK2α overexpression led to an augmented β-catenin-dependent transcription and protein levels of survivin, and consequently an enhanced resistance to apoptosis. However, CK2α-enhancing effects were reversed when an AKT mutant deficient in Ser129 phosphorylation by CK2 was co-expressed. Therefore, our results strongly suggest that CK2α-specific enhancement of β-catenin transcriptional activity as well as cell survival may depend on AKT hyperactivation by CK2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Casein Kinase II / metabolism*
  • Cell Nucleus / metabolism
  • Cell Survival
  • HEK293 Cells
  • Humans
  • Inhibitor of Apoptosis Proteins / metabolism*
  • Mutant Proteins / metabolism
  • Phosphorylation
  • Protein Binding
  • Protein Transport
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Up-Regulation
  • beta Catenin / metabolism*

Substances

  • Inhibitor of Apoptosis Proteins
  • Mutant Proteins
  • beta Catenin
  • Casein Kinase II
  • Proto-Oncogene Proteins c-akt