Inhibitors and fluorescent probes for protein kinase PKAcβ and its S54L mutant, identified in a patient with cortisol producing adenoma

Biosci Biotechnol Biochem. 2020 Sep;84(9):1839-1845. doi: 10.1080/09168451.2020.1772038. Epub 2020 Jun 7.

Abstract

Recently, a mutation was discovered in the gene PRKACB encoding the catalytic subunit β of PKA (PKAcβ) from a patient with severe Cushing's syndrome. This mutation, S54L, leads to a structural change in the glycine-rich loop of the protein. In the present study, an inhibitor with six-fold selectivity toward S54L-PKAcβ mutant over the wild-type enzyme was constructed. Moreover, we developed a fluorescent assay allowing to determine side by side the affinity of commercially available PKA inhibitors, newly synthesized compounds, and fluorescent probes toward PKAcβ and S54L-PKAcβ.

Keywords: ARC-probes; Catalytic subunit β of protein kinase A (PKAcβ); Cushing’s syndrome; wild-type-sparing ARC-precursors.

MeSH terms

  • Adenoma / genetics*
  • Adenoma / metabolism*
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / antagonists & inhibitors*
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / chemistry*
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / genetics
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / metabolism
  • Enzyme Inhibitors / pharmacology*
  • Fluorescent Dyes / chemistry*
  • Humans
  • Hydrocortisone / biosynthesis*
  • Mutation

Substances

  • Enzyme Inhibitors
  • Fluorescent Dyes
  • Cyclic AMP-Dependent Protein Kinase Catalytic Subunits
  • protein kinase A Calpha
  • Hydrocortisone