Structural basis of ribosomal S6 kinase 1 (RSK1) inhibition by S100B protein: Modulation of the extracellular signal-regulated kinase (ERK) signaling cascade in a calcium-dependent way

Gergo Gógl, Anita Alexa, Bence Kiss, Gergely Katona, Mihály Kovács, Andrea Bodor, Attila Reményi, László Nyitray

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23 Citations (Scopus)


Mitogen-activated protein kinases (MAPK) promote MAPKactivated protein kinase activation. In the MAPK pathway responsible for cell growth, ERK2 initiates the first phosphorylation event on RSK1, which is inhibited by Ca2+ -binding S100 proteins in malignant melanomas. Here, we present a detailed in vitro biochemical and structural characterization of the S100B-RSK1 interaction. The Ca2+-dependent binding of S100B to the calcium/calmodulin-dependent protein kinase (CaMK)-type domain of RSK1 is reminiscent of the better known binding of calmodulin to CaMKII. Although S100BRSK1 and the calmodulin-CAMKII system are clearly distinct functionally, they demonstrate how unrelated intracellular Ca2+ -binding proteins could influence the activity of the CaMK domain-containing protein kinases. Our crystallographic, small angle x-ray scattering, and NMR analysis revealed that S100B forms a "fuzzy" complex with RSK1 peptide ligands. Based on fast-kinetics experiments, we conclude that the binding involves both conformation selection and induced fit steps. Knowledge of the structural basis of this interaction could facilitate therapeutic targeting of melanomas.

Original languageEnglish
Pages (from-to)11-27
Number of pages17
JournalJournal of Biological Chemistry
Issue number1
Publication statusPublished - Jan 1 2016


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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