title: Computational and Biochemical Discovery of RSK2 as a Novel Target for Epigallocatechin Gallate (EGCG).
abstract: The most active anticancer component in green tea is epigallocatechin-3-gallate (EGCG). Protein interaction with EGCG is a critical step for mediating the effects of EGCG on the regulation of various key molecules involved in signal transduction. By using computational docking screening methods for protein identification, we identified a serine/threonine kinase, 90-kDa ribosomal S6 kinase (RSK2), as a novel molecular target of EGCG. RSK2 includes two kinase catalytic domains in the N-terminal (NTD) and the C-terminal (CTD) and RSK2 full activation requires phosphorylation of both terminals. The computer prediction was confirmed by an in vitro kinase assay in which EGCG inhibited RSK2 activity in a dose-dependent manner. Pull-down assay results showed that EGCG could bind with RSK2 at both kinase catalytic domains in vitro and ex vivo. Furthermore, results of an ATP competition assay and a computer-docking model showed that EGCG binds with RSK2 in an ATP-dependent manner. In RSK2+/+ and RSK2-/- murine embryonic fibroblasts, EGCG decreased viability only in the presence of RSK2. EGCG also suppressed epidermal growth factor-induced neoplastic cell transformation by inhibiting phosphorylation of histone H3 at Ser10. Overall, these results indicate that RSK2 is a novel molecular target of EGCG.
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Hanyong
authors.initials: H
authors.lastname: Chen
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Ke
authors.initials: K
authors.lastname: Yao
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Chang
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Shim
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Hong-Gyum
authors.initials: HG
authors.lastname: Kim
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Margarita
authors.initials: M
authors.lastname: Malakhova
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Dong-Joon
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Bode
authors.affiliation: The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, MN, 55912, United States of America.
authors.forename: Zigang
authors.initials: Z
authors.lastname: Dong
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D020134:Catalytic Domain; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D019295:Computational Biology; D004353:Drug Evaluation, Preclinical; D004815:Epidermal Growth Factor / Q000494:pharmacology; D051379:Mice; D062105:Molecular Docking Simulation; D058990:Molecular Targeted Therapy; D047428:Protein Kinase Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*
chemical_list: D047428:Protein Kinase Inhibitors; D004815:Epidermal Growth Factor; D000255:Adenosine Triphosphate; D002392:Catechin; C045651:epigallocatechin gallate; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C069330:ribosomal protein S6 kinase, 90kDa, polypeptide 3