研究者詳細 - 曲　正樹

Transcriptional, biochemical, and immunohistochemical analyses of CaMKKβ/2 splice variants that co-localize with CaMKIV in spermatids 査読

Satomi Ohtsuka, Yumi Miyai, Hiroyuki Mima, Masaki Magari, Yoichi Chiba, Futoshi Suizu, Hiroyuki Sakagami, Masaki Ueno, Hiroshi Tokumitsu

Cell Calcium 102820 - 102820 2024年1月

Rapid detection of calmodulin/target interaction via the proximity biotinylation method. 査読国際誌

Kento Nlandu Nakamura, Haruki Yamauchi, Hiroyuki Mima, Yerun Chen, Satomi Ohtsuka, Masaki Magari, Ryo Morishita, Hiroshi Tokumitsu

Biochemical and biophysical research communications 659 29 - 33 2023年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

Calmodulin (CaM) is known to function as a central signal transducer in calcium-mediated intracellular pathways. In this study, a fusion molecule of a recently developed proximity biotinylation enzyme (AirID) with rat CaM (AirID-CaM) was expressed and purified to near homogeneity using an E. coli expression system to examine the physical interactions between CaM and its target proteins by converting the interaction to biotinylation of CaM targets under nondenatured conditions. AirID-CaM catalyzed a Ca2+-dependent biotinylation of a target protein kinase (Ca2+/CaM-dependent protein kinase kinase α/1, CaMKKα/1) in vitro, which was suppressed by the addition of excess amounts of CaM, and AirID alone did not catalyze the biotinylation of CaMKKα/1, indicating that the biotinylation of CaMKKα/1 by AirID-CaM likely occurs in an interaction-dependent manner. Furthermore, we also observed the Ca2+-dependent biotinylation of GST-CaMKIα and GST-CaMKIV by AirID-CaM, suggesting that AirID-CaM can be useful for the rapid detection of CaM/target interactions with relatively high sensitivity.

DOI： 10.1016/j.bbrc.2023.03.072

The immunoreceptor SLAMF8 promotes the differentiation of follicular dendritic cell-dependent monocytic cells with B cell-activating ability. 査読国際誌

Masaki Magari, Miku Nishioka, Tomomi Hari, Sayaka Ogawa, Kaho Takahashi, Naoya Hatano, Naoki Kanayama, Junichiro Futami, Hiroshi Tokumitsu

FEBS letters 2022年8月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Follicular dendritic cells (FDCs) play a crucial role in generating high-affinity antibody-producing B cells during the germinal center (GC) reaction. Herein, we analysed the altered gene expression profile of a mouse FDC line, FL-Y, following lymphotoxin β receptor stimulation, and observed increased Slam-family member 8 (Slamf8) mRNA expression. Forced Slamf8 expression and SLAMF8-Fc addition enhanced the ability of FL-Y cells to induce FDC-induced monocytic cell (FDMC) differentiation. FDMCs accelerated GC-phenotype proliferation in cultured B cells, suggesting that they are capable of promoting GC responses. Furthermore, a pulldown assay showed that SLAMF8-Fc could bind to SLAMF8-His. Overall, the homophilic interaction of SLAMF8 promotes FDMC differentiation and SLAMF8 might act as a novel regulator of GC responses by regulating FDMC differentiation.

DOI： 10.1002/1873-3468.14468

Substrate recognition by Arg/Pro‐rich insert domain in calcium/calmodulin‐dependent protein kinase kinase for target protein kinases 査読

Riku Kaneshige, Satomi Ohtsuka, Yuhei Harada, Issei Kawamata, Masaki Magari, Naoki Kanayama, Naoya Hatano, Hiroyuki Sakagami, Hiroshi Tokumitsu

The FEBS Journal 2022年5月

Conformation-Dependent Reversible Interaction of Ca²⁺/Calmodulin-Dependent Protein Kinase Kinase with an Inhibitor, TIM-063 査読

Satomi Ohtsuka, Taisei Okumura, Yuna Τabuchi, Tomoyuki Miyagawa, Naoki Kanayama, Masaki Magari, Naoya Hatano, Hiroyuki Sakagami, Futoshi Suizu, Teruhiko Ishikawa, Hiroshi Tokumitsu

Biochemistry 2022年3月

Oligomerization of Ca2+/calmodulin-dependent protein kinase kinase 査読

Yusei Fukumoto, Yuhei Harada, Satomi Ohtsuka, Naoki Kanayama, Masaki Magari, Naoya Hatano, Hiroyuki Sakagami, Hiroshi Tokumitsu

Biochemical and Biophysical Research Communications 587 160 - 165 2022年1月

Regulation of the tubulin polymerization-promoting protein by Ca2+/S100 proteins. 査読国際誌

Seita Doi, Naoki Fujioka, Satomi Ohtsuka, Rina Kondo, Maho Yamamoto, Miwako Denda, Masaki Magari, Naoki Kanayama, Naoya Hatano, Ryo Morishita, Takafumi Hasegawa, Hiroshi Tokumitsu

Cell calcium 96 102404 - 102404 2021年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

To elucidate S100 protein-mediated signaling pathways, we attempted to identify novel binding partners for S100A2 by screening protein arrays carrying 19,676 recombinant glutathione S-transferase (GST)-fused human proteins with biotinylated S100A2. Among newly discovered putative S100A2 interactants, including TMLHE, TRH, RPL36, MRPS34, CDR2L, OIP5, and MED29, we identified and characterized the tubulin polymerization-promoting protein (TPPP) as a novel S100A2-binding protein. We confirmed the interaction of TPPP with Ca2+/S100A2 by multiple independent methods, including the protein array method, S100A2 overlay, and pulldown assay in vitro and in transfected COS-7 cells. Based on the results from the S100A2 overlay assay using various GST-TPPP mutants, the S100A2-binding region was identified in the C-terminal (residues 111-160) of the central core domain of a monomeric form of TPPP that is involved in TPPP dimerization. Chemical cross-linking experiments indicated that S100A2 suppresses dimer formation of His-tagged TPPP in a dose-dependent and a Ca2+-dependent manner. In addition to S100A2, TPPP dimerization is disrupted by other multiple S100 proteins, including S100A6 and S100B, in a Ca2+-dependent manner but not by S100A4. This is consistent with the fact that S100A6 and S100B, but not S100A4, are capable of interacting with GST-TPPP in the presence of Ca2+. Considering these results together, TPPP was identified as a novel target for S100A2, and it is a potential binding target for other multiple S100 proteins, including S100A6 and S100B. Direct binding of the S100 proteins with TPPP may cause disassembly of TPPP dimer formation in response to the increasing concentration of intracellular Ca2+, thus resulting in the regulation of the physiological function of TPPP, such as microtubule organization.

DOI： 10.1016/j.ceca.2021.102404

Identification and Biochemical Characterization of High Mobility Group Protein 20A as a Novel Ca2+/S100A6 Target. 査読国際誌

Maho Yamamoto, Rina Kondo, Haruka Hozumi, Seita Doi, Miwako Denda, Masaki Magari, Naoki Kanayama, Naoya Hatano, Ryo Morishita, Hiroshi Tokumitsu

Biomolecules 11 ( 4 ) 2021年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

During screening of protein-protein interactions, using human protein arrays carrying 19,676 recombinant glutathione s-transferase (GST)-fused human proteins, we identified the high-mobility protein group 20A (HMG20A) as a novel S100A6 binding partner. We confirmed the Ca2+-dependent interaction of HMG20A with S100A6 by the protein array method, biotinylated S100A6 overlay, and GST-pulldown assay in vitro and in transfected COS-7 cells. Co-immunoprecipitation of S100A6 with HMG20A from HeLa cells in a Ca2+-dependent manner revealed the physiological relevance of the S100A6/HMG20A interaction. In addition, HMG20A has the ability to interact with S100A1, S100A2, and S100B in a Ca2+-dependent manner, but not with S100A4, A11, A12, and calmodulin. S100A6 binding experiments using various HMG20A mutants revealed that Ca2+/S100A6 interacts with the C-terminal region (residues 311-342) of HMG20A with stoichiometric binding (HMG20A:S100A6 dimer = 1:1). This was confirmed by the fact that a GST-HMG20A mutant lacking the S100A6 binding region (residues 311-347, HMG20A-ΔC) failed to interact with endogenous S100A6 in transfected COS-7 cells, unlike wild-type HMG20A. Taken together, these results identify, for the first time, HMG20A as a target of Ca2+/S100 proteins, and may suggest a novel linkage between Ca2+/S100 protein signaling and HMG20A function, including in the regulation of neural differentiation.

DOI： 10.3390/biom11040510

Development and characterization of novel molecular probes for Ca2+/calmodulin-dependent protein kinase kinase, derived from STO-609. 査読国際誌

Satomi Ohtsuka, Yui Ozeki, Moeno Fujiwara, Tomoyuki Miyagawa, Naoki Kanayama, Masaki Magari, Naoya Hatano, Futoshi Suizu, Teruhiko Ishikawa, Hiroshi Tokumitsu

Biochemistry 59 ( 17 ) 1701 - 1710 2020年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) activates particular multifunctional kinases including CaMKI, CaMKIV, and 5'AMP-activated protein kinase (AMPK), resulting in the regulation of various Ca2+-dependent cellular processes including neuronal, metabolic, and pathophysiological pathways. Herein we developed and characterized a novel pan-CaMKK inhibitor, TIM-063 (2-hydroxy-3-nitro-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one) derived from STO-609 (7H-benzimidazo[2,1-a]benz[de]isoquinoline-7-one-3-carboxylic acid), and an inactive analog (TIM-062) as molecular probes for the analysis of CaMKK-mediated cellular responses. Unlike STO-609, TIM-063 had an inhibitory activity against CaMKK isoforms (CaMKKα and β) with a similar potency (Ki = 0.35 µM for CaMKKα and Ki = 0.2 µM for CaMKKβ) in vitro. Two TIM-063 analogues lacking a nitro group (TIM-062) or a hydroxy group (TIM-064) completely impaired CaMKK inhibitory activities, indicating that both substituents are necessary for the CaMKK inhibitory activity of TIM-063. Enzymatic analysis revealed that TIM-063 is an ATP-competitive inhibitor that directly targets the catalytic domain of CaMKK, similar to STO-609. TIM-063 suppressed the ionomycin-induced phosphorylation of exogenously expressed CaMKI, CaMKIV and endogenous AMPKα in HeLa cells with an IC50 of ~0.3 µM, and it suppressed the CaMKK isoforms-mediated CaMKIV phosphorylation in transfected COS-7 cells. Thus, TIM-063, but not the inactive analogue (TIM-062), displayed cell permeability and the ability to inhibit CaMKK activity in cells. Taken together, these results indicate that TIM-063 could be a useful tool for the precise analysis of CaMKK-mediated signaling pathways and may be a promising lead compound for the development of therapeutic agents for the treatment of CaMKK-related diseases.

DOI： 10.1021/acs.biochem.0c00149

Phosphorylation and dephosphorylation of Ca2+/calmodulin-dependent protein kinase kinase β at Thr144 in HeLa cells. 査読国際誌

Shota Takabatake, Yusei Fukumoto, Satomi Ohtsuka, Naoki Kanayama, Masaki Magari, Hiroyuki Sakagami, Naoya Hatano, Hiroshi Tokumitsu

Biochemical and biophysical research communications 2020年2月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ) acts as a regulatory kinase that phosphorylates and activates multiple downstream kinases including CaMKI, CaMKIV, 5'AMP-activated protein kinase (AMPK) and protein kinase B (PKB), resulting in regulation of wide variety of Ca2+-dependent physiological responses under normal and pathological conditions. CaMKKβ is regulated by Ca2+/calmodulin-binding, autophosphorylation, and transphosphorylation by multiple protein kinases including cAMP-dependent protein kinase (PKA). In this report, we found that phosphorylation of CaMKKβ is dynamically regulated by protein phosphatase/kinase system in HeLa cells. Global phosphoproteomic analysis revealed the constitutive phosphorylation at 8 Ser residues including Ser128, 132, and 136 in the N-terminal regulatory domain of rat CaMKKβ in unstimulated HeLa cells as well as inducible phosphorylation of Thr144 in the cells treated with a phosphatase inhibitor, okadaic acid (OA). Thr144 phosphorylation in CaMKKβ has shown to be rapidly induced by OA treatment in a time- and dose-dependent manner in transfected HeLa cells, indicating that Thr144 in CaMKKβ is maintained unphosphorylated state by protein phosphatase(s). We confirmed that in vitro dephosphorylation of pThr144 in CaMKKβ by protein phosphatase 2A and 1. We also found that the pharmacological inhibition of protein phosphatase(s) significantly induces CaMKKβ-phosphorylating activity (at Thr144) in HeLa cell lysates as well as in intact cells; however, it was unlikely that this activity was catalyzed by previously identified Thr144-kinases, such as AMPK and PKA. Taken together, these results suggest that the phosphorylation and dephosphorylation of Thr144 in CaMKKβ is dynamically regulated by multiple kinases/phosphatases signaling resulting in fine-tuning of the enzymatic property.

DOI： 10.1016/j.bbrc.2020.02.056

Regulation of Ca²⁺/calmodulin-dependent protein kinase kinase β by cAMP signaling. 査読国際誌

Takabatake S, Ohtsuka S, Sugawara T, Hatano N, Kanayama N, Magari M, Sakagami H, Tokumitsu H

Biochimica et biophysica acta. General subjects 1863 ( 4 ) 672 - 680 2019年4月

Interleukin 34 (IL-34) cell-surface localization regulated by the molecular chaperone 78-kDa glucose-regulated protein facilitates the differentiation of monocytic cells. 査読

Ogawa S, Matsuoka Y, Takada M, Matsui K, Yamane F, Kubota E, Yasuhara S, Hieda K, Kanayama N, Hatano N, Tokumitsu H, Magari M

The Journal of biological chemistry 294 ( 7 ) 2386 - 2396 2019年2月

Interaction of S100A6 with Target Proteins In Vitro and in Living Cells. 査読

Sakane K, Yamaguchi F, Tsuchiya M, Kondo R, Kanayama N, Magari M, Hatano N, Kobayashi R, Tokumitsu H

Methods in molecular biology (Clifton, N.J.) 1929 367 - 377 2019年

AMP-activated protein kinase-mediated feedback phosphorylation controls the Ca²⁺/calmodulin (CaM) dependence of Ca²⁺/CaM-dependent protein kinase kinase β. 査読

Nakanishi A, Hatano N, Fujiwara Y, Bin Shari A, Takabatake S, Akano H, Kanayama N, Magari M, Nozaki N, Tokumitsu H

The Journal of Biological Chemistry 292 ( 48 ) 19804 - 19813 2017年12月

Identification and characterization of a centrosomal protein, FOR20 as a novel S100A6 target 査読

Kyohei Sakane, Miyu Nishiguchi, Miwako Denda, Fuminori Yamagchi, Masaki Magari, Naoki Kanayama, Ryo Morishita, Hiroshi Tokumitsu

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 491 ( 4 ) 980 - 985 2017年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

S100A6 is a Ca2+-signal transducer that interacts with numerous proteins and regulates their biochemical functions. Here we identified a centrosomal protein, FOR20 (FOP-related protein of 20 kDa) as a novel S100A6 target by screening protein microarrays carrying 19,676 recombinant GST-fused human proteins. Binding experiments revealed that S100A6 interacts with the N-terminal region (residues 1-30) of FOR20 in a Ca2+-dependent manner in vitro and in living cells. Several S100 proteins including S100A1, A2, A4, All, B also exhibited Ca2+-dependent interactions with FOR20 as well as S100A6. We found that two distantly related centrosomal proteins, FOP and OFD1, also possess N-terminal regions with a significant sequence similarity to the putative S100A6-binding site (residues 1-30) in FOR20 and are capable of binding to S100A6 in a Ca2+-dependent manner. Taken together, these results may indicate that S100A6 interacts with FOR20 and related centrosomal proteins through a conserved N-terminal domain, suggesting a novel Ca2+-dependent regulation of centrosomal function. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2017.07.161

Germinal center B cell development has distinctly regulated stages completed by disengagement from T cell help 査読

Ting-ting Zhang, David G. Gonzalez, Christine M. Cote, Steven M. Kerfoot, Shaoli Deng, Yuqing Cheng, Masaki Magari, Ann M. Haberman

ELIFE 6 255 - 267 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELIFE SCIENCES PUBLICATIONS LTD

To reconcile conflicting reports on the role of CD40 signaling in germinal center (GC) formation, we examined the earliest stages of murine GC B cell differentiation. Peri-follicular GC precursors first expressed intermediate levels of BCL6 while co-expressing the transcription factors RelB and IRF4, the latter known to repress Bcl6 transcription. Transition of GC precursors to the BCL6(hi) follicular state was associated with cell division, although the number of required cell divisions was immunogen dose dependent. Potentiating T cell help or CD40 signaling in these GC precursors actively repressed GC B cell maturation and diverted their fate towards plasmablast differentiation, whereas depletion of CD4(+) T cells promoted this initial transition. Thus while CD40 signaling in B cells is necessary to generate the immediate precursors of GC B cells, transition to the BCL6(hi) follicular state is promoted by a regional and transient diminution of T cell help.

DOI： 10.7554/eLife.19552

SRSF1-3 contributes to diversification of the immunoglobulin variable region gene by promoting accumulation of AID in the nucleus 査読

Yuka Kawaguchi, Hiroaki Nariki, Naoko Kawamoto, Yuichi Kanehiro, Satoshi Miyazaki, Mari Suzuki, Masaki Magari, Hiroshi Tokumitsu, Naoki Kanayama

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 485 ( 2 ) 261 - 266 2017年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

Activation-induced cytidine deaminase (AID) is essential for diversification of the Ig variable region (IgV). AID is excluded from the nucleus, where it normally functions. However, the molecular mechanisms responsible for regulating AID localization remain to be elucidated. The SR-protein splicing factor SRSF1 is a nucleocytoplasmic shuttling protein, a splicing isoform of which called SRSF1-3, has previously been shown to contribute to IgV diversification in chicken DT40 cells. In this study, we examined whether SRSFI-3 functions in IgV diversification by promoting nuclear localization of AID. AID expressed alone was localized predominantly in the cytoplasm. In contrast, co-expression of AID with SRSFI-3 led to the nuclear accumulation of both AID and SRSF1-3 and the formation of a protein complex that contained them both, although SRSF1-3 was dispensable for nuclear import of AID. Expression of either SRSF1-3 or a C-terminally-truncated AID mutant increased IgV diversification in DT40 cells. However, over expression of exogenous SRSF1-3 was unable to further enhance IgV diversification in DT40 cells expressing the truncated AID mutant, although SRSFI-3 was able to form a protein complex with the AID mutant. These results suggest that SRSF1-3 promotes nuclear localization of AID probably by forming a nuclear protein complex, which might stabilize nuclear AID and induce IgV diversification in an AID C terminus-dependent manner. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bbrc.2017.02.097

Identification of striated muscle activator of Rho signaling (STARS) as a novel calmodulin target by a newly developed genome-wide screen 査読

Yusui Furuya, Miwako Denda, Kyohei Sakane, Tomoko Ogusu, Sumio Takahashi, Masaki Magari, Naoki Kanayama, Ryo Morishita, Hiroshi Tokumitsu

CELL CALCIUM 60 ( 1 ) 32 - 40 2016年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHURCHILL LIVINGSTONE

To search for novel target(s) of the Ca2+-signaling transducer, calmodulin (CaM), we performed a newly developed genome-wide CaM interaction screening of 19,676 GST-fused proteins expressed in human. We identified striated muscle activator of Rho signaling (STARS) as a novel CaM target and characterized its CaM binding ability and found that the Ca2+/CaM complex interacted stoichiometrically with the N-terminal region (Ala13-Gln35) of STARS in vitro as well as in living cells. Mutagenesis studies identified Ile20 and Trp33 as the essential hydrophobic residues in CaM anchoring. Furthermore, the CaM binding deficient mutant (Ile20Ala, Trp33Ala) of STARS further enhanced its stimulatory effect on SRF-dependent transcriptional activation. These results suggest a connection between Ca2+-signaling via excitation-contraction coupling and the regulation of STARS-mediated gene expression in muscles. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ceca.2016.04.004

Differential AMP-activated Protein Kinase (AMPK) Recognition Mechanism of Ca2+/Calmodulin-dependent Protein Kinase Kinase Isoforms 査読

Yuya Fujiwara, Yoshinori Kawaguchi, Tomohito Fujimoto, Naoki Kanayama, Masaki Magari, Hiroshi Tokumitsu

JOURNAL OF BIOLOGICAL CHEMISTRY 291 ( 26 ) 13802 - 13808 2016年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) is a known activating kinase for AMP-activated protein kinase (AMPK). In vitro, CaMKK phosphorylates Thr(172) in the AMPK subunit more efficiently than CaMKK, with a lower K-m (approximate to 2 m) for AMPK, whereas the CaMKI phosphorylation efficiencies by both CaMKKs are indistinguishable. Here we found that subdomain VIII of CaMKK is involved in the discrimination of AMPK as a native substrate by measuring the activities of various CaMKK/CaMKK chimera mutants. Site-directed mutagenesis analysis revealed that Leu(358) in CaMKK/Ile(322) in CaMKK confer, at least in part, a distinct recognition of AMPK but not of CaMKI.

DOI： 10.1074/jbc.M116.727867