5csj
S100B-RSK1 crystal structure B
Structural highlights
FunctionS100B_HUMAN Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites. Binds to and initiates the activation of STK38 by releasing autoinhibitory intramolecular interactions within the kinase. Interaction with AGER after myocardial infarction may play a role in myocyte apoptosis by activating ERK1/2 and p53/TP53 signaling (By similarity). Could assist ATAD3A cytoplasmic processing, preventing aggregation and favoring mitochondrial localization.[1] Publication Abstract from PubMedMitogen-activated protein kinases (MAPK) promote MAPK activated protein kinase (MAPKAPK) activation. In the MAPK pathway responsible to cell growth, ERK2 initiates the first phosphorylation event on RSK1, which is inhibited by calcium-binding S100 proteins in malignant melanomas. Here we present a detailed in vitro biochemical and structural characterization of the S100B-RSK1 interaction. The calcium-dependent binding of S100B to the calcium/calmodulin dependent protein kinase (CaMK)-type domain of RSK1 is reminiscent to the better known binding of calmodulin to CaMKII. Although S100B-RSK1 and the calmodulin-CAMKII system are clearly distinct functionally, they demonstrate how unrelated intracellular Ca2+ binding proteins could influence the activity of CaMK domain containing protein kinases. Our crystallographic, small angle X-ray scattering (SAXS) 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. 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.,Gogl G, Alexa A, Kiss B, Katona G, Kovacs M, Bodor A, Remenyi A, Nyitray L J Biol Chem. 2015 Nov 2. pii: jbc.M115.684928. PMID:26527685[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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