title: Structural insights into the recruitment of SMRT by the corepressor SHARP under phosphorylative regulation.
abstract: The transcriptional corepressors SMRT/NCoR, components of histone deacetylase complexes, interact with nuclear receptors and many other transcription factors. SMRT is a target for the ubiquitously expressed protein kinase CK2, which is known to phosphorylate a wide variety of substrates. Increasing evidence suggests that CK2 plays a regulatory role in many cellular events, particularly, in transcription. However, little is known about the precise mode of action involved. Here, we report the three-dimensional structure of a SMRT/HDAC1-associated repressor protein (SHARP) in complex with phosphorylated SMRT, as determined by solution NMR. Phosphorylation of the CK2 site on SMRT significantly increased affinity for SHARP. We also confirmed the significance of CK2 phosphorylation by reporter assay and propose a mechanism involving the process of phosphorylation acting as a molecular switch. Finally, we propose that the SPOC domain functions as a phosphorylation binding module.
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan.
authors.forename: Suzuka
authors.initials: S
authors.lastname: Mikami
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Kanaba
authors.affiliation: Institute of Microbial Chemistry, Tokyo 3-14-23 Kamiosaki, Shinagawa-ku 141-0021, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Takizawa
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan.
authors.forename: Ayaho
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan; Graduate School of Bioscience, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Maesaki
authors.affiliation: Institute of Microbial Chemistry, Tokyo 3-14-23 Kamiosaki, Shinagawa-ku 141-0021, Japan.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiosawa Hachioji 192-0397, Japan. Electronic address: mishima-masaki@tmu.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D001665:Binding Sites; D047390:Casein Kinase II / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D056985:Nuclear Receptor Co-Repressor 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C539130:NCOR2 protein, human; D009687:Nuclear Proteins; D056985:Nuclear Receptor Co-Repressor 2; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C476510:SPEN protein, human; D047390:Casein Kinase II