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Molecular mechanism of Raf kinase inhibitory protein regulation by cAMP‐dependent protein kinase (802.25)
Author(s) -
Ong Colin,
Masterson Larry,
Kim Jonggul,
Gomes Suzana,
Veglia Gianluigi,
Rosner Marsha
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.802.25
Subject(s) - protein kinase a , protein subunit , c raf , chemistry , kinase , phosphorylation , cyclin dependent kinase complex , microbiology and biotechnology , biochemistry , mitogen activated protein kinase kinase , biology , gene
Raf Kinase Inhibitory Protein (RKIP), a 21 kDa protein and member of phosphatidylethanolamine binding protein (PEBP) family, regulates GPCR, MAPK, and NFκB pathways and is a metastasis suppressor. Although, kinases such as ERK2 and PKCα have been shown to phosphorylate RKIP, structural data on the protein kinase‐RKIP interaction are still lacking. Here we report that another kinase, PKA, phosphorylates RKIP at residue 51, triggering a feedback loop, and we determine the structural model of RKIP‐PKA catalytic subunit. Using different biophysical approaches including Nuclear Magnetic Resonance (NMR), Paramagnetic Relaxation Enhancements (PREs) and molecular modeling, we identify the binding interface between RKIP and PKA catalytic subunit. Chemical shift mapping and site directed mutagenesis studies revealed residues within RKIP that are critical to the catalysis and binding mediated by PKA catalytic subunit. As the first description of PKA binding to a full‐length physiological substrate, these results have wide applicability to the mechanism of PKA catalysis Grant Funding Source : Supported by NIH grant GM087630 to Marsha Rich Rosner, NIH grant GM100310 to Gianluigi Veglia