Research activity information

• Age-Progressive Synaptic and Axonal Dysregulation Induced by Purkinje Cell-Targeted AAV Expression of SCA14 PKCγ in Mice.

  Naoko Adachi, Izumi Koganemaru, Feng Wanying, Naoya Matsushita, Tomoyoshi Nakayama, Takahiro Seki, Ayumu Konno, Hirokazu Hirai, Naoaki Saito, Takehiko Ueyama

  Spinocerebellar ataxia type 14 (SCA14) is an autosomal-dominant disorder caused by more than 80 PRKCG missense variants encoding protein kinase Cγ (PKCγ), a serine/threonine kinase highly enriched in Purkinje cells (PCs). Despite typically late onset and slow progression, the molecular basis of age-related decline remains unclear. We used a somatic in vivo approach to express wild-type (WT) PKCγ-GFP or the prototypical G128D PKCγ-GFP selectively in PCs of neonatal mice via an adeno-associated virus (AAV) under a PC-specific promoter. G128D PKCγ-GFP formed cytoplasmic aggregates, mislocalized PCs during development, and produced gait deficits by 4 weeks that worsened with age, despite preserved PC counts and overall cerebellar volume at 1.5 years. Immunohistochemistry revealed a selective vulnerability of climbing-fiber (CF) input: vesicular glutamate transporter 2 (VGLUT2), a marker of CF synapses, declined significantly from 12 to 60 weeks in G128D mice, and the VGLUT2-positive innervation field was narrower than age-matched WT at both time points. By contrast, the glutamate/aspartate transporter GLAST in Bergmann-glial radial processes was reduced predominantly at 12 weeks in G128D mice. The δ2 glutamate receptor (GluD2) at parallel fibers and glial fibrillary acidic protein (GFAP) decreased with age but were comparable between expression conditions. Notably, aggregated mutant PKCγ accumulated within the axon initial segment (AIS), whose architecture progressively deteriorated; the altered AIS excluded PKCγ-GFP from distal axons and, by 60 weeks, was associated with reduced delivery of the vesicular GABA transporter (VGAT) to deep cerebellar nuclei (DCN), consistent with impaired anterograde transport. Hence, rather than overt neuronal loss, the cumulative burden of G128D-specific CF/axonal deficits and age-accentuated circuit and glial changes-reduced GLAST function and decreased GluD2-accounts for the worsening motor phenotype. This AAV-based system provides a practical platform to dissect late-onset pathogenic mechanisms and evaluate therapeutic strategies in vivo.

  Nov. 2025, Journal of neurochemistry, 169(11) (11), e70305, English, International magazine

  [Refereed]

  Scientific journal


• A facile assay for zDHHC palmitoyl transferase activation elucidates effects of mutation and modification.

  Naoko Adachi, Douglas T Hess, Takehiko Ueyama

  At least 10% of proteins constituting the human proteome are subject to S-acylation by a long-chain fatty acid, thioesterified to a Cys thiol side chain. Fatty S-acylation (prototypically, S-palmitoylation) operates across eukaryotic phylogeny and cell type. S-palmitoylation is carried out in mammalian cells by a family of 23-24 dedicated zDHHC palmitoyl transferase enzymes, and mutation of zDHHCs is associated with a number of human pathophysiologies. Activation of the zDHHCs by auto-S-palmitoylation, the transthioesterification of the active site Cys by fatty acyl-CoA, is the necessary first step in zDHHC-mediated protein S-palmitoylation. Most prior in vitro assessments of zDHHC activation have utilized purified zDHHCs, a time- and effort-intensive approach, which removes zDHHCs from their native membrane environment. We describe here a facile assay for zDHHC activation in native membranes. We overexpressed HA-tagged wild-type or mutant zDHHCs in cultured HEK293 cells and prepared a whole membrane fraction, which was incubated with fluorescent palmitoyl CoA (NBD-palmitoyl-CoA) followed by SDS-PAGE, fluorescence imaging and western blotting for HA. We show by mutational analysis that, as assayed, zDHHC auto-S-palmitoylation by NBD-palmitoyl-CoA is limited to the active site Cys. Application of the assay revealed differential effects on zDHHC activation of posttranslational zDHHC modification, and of zDHHC mutations associated with human disease, in particular cancer. Our assay provides a facile means of assessing zDHHC activation and thus of differentiating the effects of zDHHC mutation and post-translational modification on zDHHC activation versus secondary effects on zDHHC functionality resulting from altered zDHHC interaction with substrate palmitoyl-proteins.

  Jan. 2025, Journal of lipid research, 100743 - 100743, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• S-Palmitoylation of the serotonin transporter promotes its cell surface expression and serotonin uptake.

  Kana Harada, Ryoma Sho, Hiromiki Takakura, Eri Yokoyama, Reika Koyama, Yuka Yamamoto, Naoko Adachi, Shigeru Tanaka, Izumi Hide, Norio Sakai

  The neurotransmitter serotonin (5-HT) is transported back into serotonergic neurons by the serotonin transporter (SERT). SERT is a main target of antidepressants, and much effort has therefore focused on finding relationships between SERT and depression. However, it is not fully understood how SERT is regulated at the cellular level. Here, we report post-translational regulation of SERT by S-palmitoylation, in which palmitate is covalently attached to cysteine residues of proteins. Using AD293 cells (a human embryonic kidney 293-derived cell line with improved cell adherence) transiently transfected with FLAG-tagged human SERT, we observed S-palmitoylation of immature SERT containing high-mannose type N-glycans or no N-glycan, which is presumed to be localized in the early secretory pathway, such as the endoplasmic reticulum. Mutational analysis by alanine substitutions shows that S-palmitoylation of immature SERT occurs at least at Cys-147 and Cys-155, juxtamembrane cysteine residues within the first intracellular loop. Furthermore, mutation of Cys-147 reduced cellular uptake of a fluorescent SERT substrate that mimics 5-HT without decreasing SERT on the cell surface. On the other hand, combined mutation of Cys-147 and Cys-155 inhibited SERT surface expression and reduced the uptake of the 5-HT mimic. Thus, S-palmitoylation of Cys-147 and Cys-155 is important for both the cell surface expression and 5-HT uptake capacity of SERT. Given the importance of S-palmitoylation in brain homeostasis, further investigation of SERT S-palmitoylation could provide new insights into the treatment of depression.

  Jun. 2023, Biochemical and biophysical research communications, 662, 58 - 65, English, International magazine

  [Refereed]

  Scientific journal


• S-Palmitoylation of Tyrosinase at Cysteine500 Regulates Melanogenesis.

  Yoko Niki, Naoko Adachi, Masaki Fukata, Yuko Fukata, Shinichiro Oku, Chieko Makino-Okamura, Seiji Takeuchi, Kazumasa Wakamatsu, Shosuke Ito, Lieve Declercq, Daniel B Yarosh, Tomas Mammone, Chikako Nishigori, Naoaki Saito, Takehiko Ueyama

  Palmitoylation is a lipid modification involving the attachment of palmitic acid to a cysteine residue, thereby affecting protein function. We investigated the effect of palmitoylation of tyrosinase, the rate-limiting enzyme in melanin synthesis, using a human three-dimensional skin model system and melanocyte culture. The palmitoylation inhibitor, 2-bromopalmitate, increased melanin content and tyrosinase protein levels in melanogenic cells by suppressing tyrosinase degradation. The palmitoylation site was Cysteine500 in the C-terminal cytoplasmic tail of tyrosinase. The nonpalmitoylatable mutant, tyrosinase (C500A), was slowly degraded and less ubiquitinated than wild-type tyrosinase. Screening for the Asp-His-His-Cys (DHHC) family of proteins for tyrosinase palmitoylation suggested that DHHC2, 3, 7, and 15 are involved in tyrosinase palmitoylation. Knockdown of DHHC2, 3, or 15 increased tyrosinase protein levels and melanin content. Determination of their subcellular localization in primary melanocytes revealed that DHHC2, 3, and 15 were localized in the endoplasmic reticulum, Golgi apparatus, and/or melanosomes, whereas only DHHC2 was localized in the melanosomes. Immunoprecipitation showed that DHHC2 and DHHC3 predominantly bind to mature and immature tyrosinase, respectively. Taken together, tyrosinase palmitoylation at Cysteine500 by DHHC2, 3, and/or 15, especially DHHC2 in trans-Golgi apparatus and melanosomes and DHHC3 in the endoplasmic reticulum and cis-Golgi apparatus, regulate melanogenesis by modulating tyrosinase protein levels.

  Lead, Sep. 2022, The Journal of investigative dermatology, 143(2) (2), 317 - 327, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• S-nitrosylation is required for β2AR desensitization and experimental asthma.

  Fabio V Fonseca, Thomas M Raffay, Kunhong Xiao, Precious J McLaughlin, Zhaoxia Qian, Zachary W Grimmett, Naoko Adachi, Benlian Wang, Alfred Hausladen, Brian A Cobb, Rongli Zhang, Douglas T Hess, Benjamin Gaston, Nevin A Lambert, James D Reynolds, Richard T Premont, Jonathan S Stamler

  The β2-adrenergic receptor (β2AR), a prototypic G-protein-coupled receptor (GPCR), is a powerful driver of bronchorelaxation, but the effectiveness of β-agonist drugs in asthma is limited by desensitization and tachyphylaxis. We find that during activation, the β2AR is modified by S-nitrosylation, which is essential for both classic desensitization by PKA as well as desensitization of NO-based signaling that mediates bronchorelaxation. Strikingly, S-nitrosylation alone can drive β2AR internalization in the absence of traditional agonist. Mutant β2AR refractory to S-nitrosylation (Cys265Ser) exhibits reduced desensitization and internalization, thereby amplifying NO-based signaling, and mice with Cys265Ser mutation are resistant to bronchoconstriction, inflammation, and the development of asthma. S-nitrosylation is thus a central mechanism in β2AR signaling that may be operative widely among GPCRs and targeted for therapeutic gain.

  Aug. 2022, Molecular cell, 82(16) (16), 3089 - 3102, English, International magazine

  [Refereed]

  Scientific journal


• Spinocerebellar ataxia type 14 caused by a nonsense mutation in the PRKCG gene.

  Shirafuji T, Shimazaki H, Miyagi T, Ueyama T, Adachi N, Tanaka S, Hide I, Saito N, Sakai N

  Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia with myoclonus, dystonia, spasticity, and rigidity. Although missense mutations and a deletion mutation have been found in the protein kinase C gamma (PRKCG) gene encoding protein kinase C γ (PKCγ) in SCA14 families, a nonsense mutation has not been reported. The patho-mechanisms underlying SCA14 remain poorly understood. However, gain-of-function mechanisms and loss-of-function mechanisms, but not dominant negative mechanisms, were reported the patho-mechanism of SCA14. We identified the c.226C>T mutation of PRKCG, which caused the p.R76X in PKCγ by whole-exome sequencing in patients presenting cerebellar atrophy with cognitive and hearing impairment. To investigate the patho-mechanism of our case, we studied aggregation formation, cell death, and PKC inhibitory effect by confocal microscopy, western blotting with cleaved caspase 3, and pSer PKC motif antibodies, respectively. PKCγ(R76X)-GFP have aggregations the same as wild-type (WT) PKCγ-GFP. The PKCγ(R76X)-GFP inhibited PKC phosphorylation activity more than GFP alone. It also induced more apoptosis in COS7 and SH-SY5Y cells compared to WT-PKCγ-GFP and GFP. We first reported SCA14 patients with p.R76X in PKCγ who have cerebellar atrophy with cognitive and hearing impairment. Our results suggest that a dominant negative mechanism due to truncated peptides produced by p.R76X may be at least partially responsible for the cerebellar atrophy.

  Jul. 2019, Molecular and cellular neurosciences, 98, 46 - 53, English, International magazine

  [Refereed]

  Scientific journal


• Differential S-palmitoylation of the human and rodent β3-adrenergic receptors

  Adachi Naoko, Hess DT, Kaku M, Ueda C, Numa C, Saito Naoaki

  With few reported exceptions, G protein-coupled receptors (GPCRs) are modified by Cys palmitoylation (S-palmitoylation). In multiple GPCRs, S-palmitoylation targets a canonical site within the C-terminal cytoplasmic tail adjacent to the C terminus of the seventh transmembrane domain, but modification of additional sites is exemplified by the β-adrenergic receptors (βARs). The β1AR is S-palmitoylated at a second, more distal site within the C-terminal tail, and the β2AR is modified at a second site within the third intracellular loop, neither of which is conserved in other βAR isoforms. The functional roles of S-palmitoylation of disparate sites are incompletely characterized for any GPCR family. Here, we describe S-palmitoylation of the β3AR. We compared mouse and human β3ARs and found that both were S-palmitoylated at the canonical site within the C-terminal tail, Cys-358 and Cys-361/363 in mouse and human β3ARs, respectively. Surprisingly, the human β3AR was S-palmitoylated at two additional sites, Cys-153 and Cys-292 within the second and third intracellular loops, respectively. Cys-153 is apparently unique to the human β3AR, and Cys-292 is conserved primarily in primates. Mutational substitution of C-tail Cys in human but not mouse β3ARs resulted in diminished ligand-induced cAMP production. Substitution of Cys-153, Cys-292, or Cys-361/363 within the human β3AR diminished membrane-receptor abundance, but only Cys-361/363 substitution diminished membrane-receptor half-life. Thus, S-palmitoylation of different sites differentially regulates the human β3AR, and differential S-palmitoylation distinguishes human and rodent β3ARs, potentially contributing to species-specific differences in the clinical efficacy of β3AR-directed pharmacological approaches to disease.

  Feb. 2019, J Biol Chem, 294(7) (7), 2569 - 2578, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Pharmacological induction of heat shock proteins ameliorates toxicity of mutant PKCγ in spinocerebellar ataxia type 14

  Nakazono A, Adachi Naoko, Takahashi H, Seki T, Hamada D, Ueyama Takehiko, Sakai N, Saito Naoaki

  Corresponding, Sep. 2018, J Biol Chem, 293(38) (38), 14758 - 14774, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Propofol induced diverse and subtype-specific translocation of PKC families

  Takeshi Miyahara, Naoko Adachi, Takahiro Seki, Izumi Hide, Shigeru Tanaka, Naoaki Saito, Masahiro Irifune, Norio Sakai

  Japanese Pharmacological Society, May 2018, Journal of Pharmacological Sciences, 137(1) (1), 20 - 29, English, Domestic magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• The role of cysteine string protein α phosphorylation at serine 10 and 34 by protein kinase Cγ for presynaptic maintenance

  Toshihiko Shirafuji, Takehiko Ueyama, Naoko Adachi, Ken-Ichi Yoshino, Yusuke Sotomaru, Junsuke Uwada, Azumi Kaneoka, Taro Ueda, Shigeru Tanaka, Izumi Hide, Naoaki Saito, Norio Sakai

  Society for Neuroscience, Jan. 2018, Journal of Neuroscience, 38(2) (2), 278 - 290, English, International magazine

  [Refereed]

  Scientific journal


• Loss of the Phenolic Hydroxyl Group and Aromaticity from the Side Chain of Anti-Proliferative 10-Methyl-aplog-1, a Simplified Analog of Aplysiatoxin, Enhances Its Tumor-Promoting and Proinflammatory Activities

  Yusuke Hanaki, Masayuki Kikumori, Harukuni Tokuda, Mutsumi Okamura, Shingo Dan, Naoko Adachi, Naoaki Saito, Ryo C. Yanagita, Kazuhiro Irie

  Apr. 2017, MOLECULES, 22(4) (4), English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Xeroderma pigmentosum group C protein interacts with histones: regulation by acetylated states of histone H3

  Erina Kakumu, Seiya Nakanishi, Hiromi M. Shiratori, Akari Kato, Wataru Kobayashi, Shinichi Machida, Takeshi Yasuda, Naoko Adachi, Naoaki Saito, Tsuyoshi Ikura, Hitoshi Kurumizaka, Hiroshi Kimura, Masayuki Yokoi, Wataru Sakai, Kaoru Sugasawa

  Mar. 2017, GENES TO CELLS, 22(3) (3), 310 - 327, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• S-Palmitoylation of a Novel Site in the beta(2)-Adrenergic Receptor Associated with a Novel Intracellular Itinerary

  Naoko Adachi, Douglas T. Hess, Precious McLaughlin, Jonathan S. Stamler

  Lead, Sep. 2016, JOURNAL OF BIOLOGICAL CHEMISTRY, 291(38) (38), 20232 - 20246, English, International magazine

  [Refereed]

  Scientific journal


• Identification and characterization of PKCP gamma, a kinase associated with SCA14, as an amyloidogenic protein

  Hideyuki Takahashi, Naoko Adachi, Toshihiko Shirafuji, Sally Danno, Takehiko Ueyama, Michele Vendruscolo, Anton N. Shuvaev, Takuya Sugimoto, Takahiro Seki, Daizo Hamada, Kazuhiro Irie, Hirokazu Hirai, Norio Sakai, Naoaki Saito

  Jan. 2015, HUMAN MOLECULAR GENETICS, 24(2) (2), 525 - 539, English, International magazine

  [Refereed]

  Scientific journal


• The Role of Pak-Interacting Exchange Factor-beta Phosphorylation at Serines 340 and 583 by PKC gamma in Dopamine Release

  Toshihiko Shirafuji, Takehiko Ueyama, Ken-ichi Yoshino, Hideyuki Takahashi, Naoko Adachi, Yukio Ago, Ken Koda, Tetsuaki Nashida, Naoki Hiramatsu, Toshio Matsuda, Tatsushi Toda, Norio Sakai, Naoaki Saito

  Jul. 2014, JOURNAL OF NEUROSCIENCE, 34(28) (28), 9268 - 9280, English, International magazine

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Deregulation of the actin cytoskeleton and macropinocytosis in response to phorbol ester by the mutant protein kinase C gamma that causes spinocerebellar ataxia type 14

  Kazuhiro Yamamoto, Takahiro Seki, Hikaru Yamamoto, Naoko Adachi, Shigeru Tanaka, Izumi Hide, Naoaki Saito, Norio Sakai

  Apr. 2014, FRONTIERS IN PHYSIOLOGY, 5, 126 - 126, English, International magazine

  [Refereed]

  Scientific journal


• Mutant gamma PKC that causes spinocerebellar ataxia type 14 upregulates Hsp70, which protects cells from the mutant's cytotoxicity

  Kota Ogawa, Takahiro Seki, Tomoya Onji, Naoko Adachi, Shigeru Tanaka, Izumi Hide, Naoaki Saito, Norio Sakai

  Oct. 2013, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 440(1) (1), 25 - 30, English

  [Refereed]

  Scientific journal


• Elucidation of the molecular mechanism and exploration of novel therapeutics for spinocerebellar ataxia caused by mutant protein kinase Cγ

  Takahiro Seki, Naoko Adachi, Nana Abe-Seki, Takayuki Shimahara, Hideyuki Takahashi, Kazuhiro Yamamoto, Naoaki Saito, Norio Sakai

  2011, Journal of Pharmacological Sciences, 116(3) (3), 239 - 247, English

  [Refereed]

  Scientific journal


• Congo red, an amyloid-inhibiting compound, alleviates various types of cellular dysfunction triggered by mutant protein kinase cγ that causes spinocerebellar ataxia type 14 (SCA14) by inhibiting oligomerization and aggregation.

  Seki Takahiro, Takahashi Hideyuki, Yamamoto Kazuhiro, Ogawa Kota, Onji Tomoya, Adachi Naoko, Tanaka Shigeru, Hide Izumi, Saito Naoaki, Sakai Norio

  :Several missense mutations in the protein kinase Cγ (γPKC) gene have been found to cause spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that the mutant γPKC found in SCA14 is susceptible to aggregation that induces apoptotic cell death. Congo red is widely used as a histological dye for amyloid detection. Recent evidence has revealed that Congo red has the property to inhibit amyloid oligomers and fibril formation of misfolded proteins. In the present study, we examine whether Congo red inhibits aggregate formation and cytotoxicity of mutant γPKC. Congo red likely inhibits aggregate formation of mutant γPKC – green fluorescent protein (GFP) without affecting its expression level in SH-SY5Y cells. Congo red counteracts the insolubilization of recombinant mutant γPKC, suggesting that the dye inhibits aggregation of mutant γPKC by a direct mechanism. Congo red also inhibits aggregation and oligomerization of mutant γPKC-GFP in primary cultured cerebellar Purkinje cells. Moreover, the dye reverses the improper development of dendrites and inhibits apoptotic cell death in Purkinje cells that express mutant

  2010, J. Pharmacol. Sci., 114(2) (2), 33252 - 33264

  [Refereed]

  Scientific journal


• Effect of trehalose on the properties of mutant {gamma}PKC, which causes spinocerebellar ataxia type 14, in neuronal cell lines and cultured Purkinje cells.

  Seki Takahiro, Abe-Seki Nana, Kikawada Takahiro, Takahashi Hideyuki, Yamamoto Kazuhiro, Adachi Naoko, Tanaka Shigeru, Hide Izumi, Saito Naoaki, Sakai Norio

  :Several missense mutations in the protein kinase Cγ (γPKC) gene have been found to cause spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that the mutant γPKC found in SCA14 is susceptible to aggregation, which induces apoptotic cell death. The disaccharide trehalose has been reported to inhibit aggregate formation and to alleviate symptoms in cellular and animal models of Huntington disease, Alzheimer disease, and prion disease. Here, we show that trehalose can be incorporated into SH-SY5Y cells and reduces the aggregation of mutant γPKC-GFP, thereby inhibiting apoptotic cell death in SH-SY5Y cells and primary cultured Purkinje cells (PCs). Trehalose acts by directly stabilizing the conformation of mutant γPKC without affecting protein turnover. Trehalose was also found to alleviate the improper development of dendrites in PCs expressing mutant γPKC-GFP without aggregates but not in PCs with aggregates. In PCs without aggregates, trehalose improves the mobility and translocation of mutant γPKC-GFP, probably by inhibiting oligomerization and thereby alleviating the improper development of dendrites. These re

  2010, J Biol. Chem., 285(43) (43), 33252 - 33264

  [Refereed]

  Scientific journal


• Mutant protein kinase C gamma that causes spinocerebellar ataxia type 14 (SCA14) is selectively degraded by autophagy

  Kazuhiro Yamamoto, Takahiro Seki, Naoko Adachi, Tetsuya Takahashi, Shigeru Tanaka, Izumi Hide, Naoaki Saito, Norio Sakai

  Blackwell Publishing Ltd, 2010, Genes to Cells, 15(5) (5), 425 - 438, English

  [Refereed]

  Scientific journal


• Mutant gammaPKC found in spinocerebellar ataxia type 14 induces aggregate-independent maldevelopment of dendrites in primary cultured Purkinje cells.

  Seki Takahiro, Shimahara Takayuki, Yamamoto Kazuhiro, Abe Nana, Amano Taku, Adachi Naoko, Takahashi Hideyuki, Kashiwagi Kaori, Saito Naoaki, Sakai Norio

  :Missense mutations in protein kinase Cgamma (gammaPKC) gene have been found in spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that mutant gammaPKC found in SCA14 is susceptible to aggregation and induces apoptosis in cultured cell lines. In the present study, we investigated whether mutant gammaPKC formed aggregates and how mutant gammaPKC affects the morphology and survival of cerebellar Purkinje cells (PCs), which are degenerated in SCA14 patients. Adenovirus-transfected primary cultured PCs expressing mutant gammaPKC-GFP also had aggregates and underwent apoptosis. Long-term time-lapse observation revealed that PCs have a potential to eliminate aggregates of mutant gammaPKC-GFP. Mutant gammaPKC-GFP disturbed the development of PC dendrites and reduced synapse formation, regardless of the presence or absence of its aggregates. In PCs without aggregates, mutant gammaPKC-GFP formed soluble oligomers, resulting in reduced mobility and attenuated translocation of mutant gammaPKC-GFP upon stimulation. These molecular properties of mutant gammaPKC might affect the dendritic morphology in PCs, and be involved in the p

  2009, Neurobiol. Dis., 33(2) (2), 260 - 273

  [Refereed]

  Scientific journal


• Diacylglycerol kinase beta accumulates on the perisynaptic site of medium spiny neurons in the striatum

  Yasukazu Hozumi, Masahiro Fukaya, Naoko Adachi, Naoaki Saito, Koichi Otani, Hisatake Kondo, Masahiko Watanabe, Kaoru Goto

  Dec. 2008, EUROPEAN JOURNAL OF NEUROSCIENCE, 28(12) (12), 2409 - 2422, English

  [Refereed]

  Scientific journal


• Protein kinase C epsilon: function in neurons

  Yasuhito Shirai, Naoko Adachi, Naoaki Saito

  Aug. 2008, FEBS JOURNAL, 275(16) (16), 3988 - 3994, English

  [Refereed]


• Enzymological analysis of mutant protein kinase C gamma causing spinocerebellar ataxia type 14 and dysfunction in Ca2+ homeostasis

  Naoko Adachi, Takeshi Kobayashi, Hideyuki Takahashi, Takumi Kawasaki, Yasuhito Shirai, Takehiko Ueyama, Toshio Matsuda, Takahiro Seki, Norio Sakai, Naoaki Saito

  Lead, Jul. 2008, JOURNAL OF BIOLOGICAL CHEMISTRY, 283(28) (28), 19854 - 19863, English

  [Refereed]

  Scientific journal


• Aggregate formation of mutant protein kinase C gamma found in spinocerebellar ataxia type 14 impairs ubiquitin-proteasome system and induces endoplasmic reticulum stress

  Takahiro Seki, Hideyuki Takahashi, Naoko Adachi, Nana Abe, Takayuki Shimahara, Naoaki Saito, Norio Sakai

  Dec. 2007, EUROPEAN JOURNAL OF NEUROSCIENCE, 26(11) (11), 3126 - 3140, English

  [Refereed]

  Scientific journal


• R659S mutation of gamma PKC is susceptible to cell death: Implication of this mutation/polymorphism in the pathogenesis of retinitis pigmentosa

  Hideki Mochizuki, Takahiro Seki, Naoko Adachi, Naoaki Saito, Hiromu K. Mishima, Norio Sakai

  Dec. 2006, NEUROCHEMISTRY INTERNATIONAL, 49(7) (7), 669 - 675, English

  [Refereed]

  Scientific journal


• Immunocytochemical localization of a neuron-specific diacylglycerol kinase beta and gamma in the developing rat brain

  N Adachi, M Oyasu, T Taniguchi, Y Yamaguchi, R Takenaka, Y Shirai, N Saito

  Lead, Oct. 2005, MOLECULAR BRAIN RESEARCH, 139(2) (2), 288 - 299, English

  [Refereed]

  Scientific journal


• Mutant protein kinase C gamma found in spinocerebellar ataxia type 14 is susceptible to aggregation and causes cell death

  T Seki, N Adachi, Y Ono, H Mochizuki, K Hiramoto, T Amano, H Matsubayashi, M Matsumoto, H Kawakami, N Saito, N Sakai

  Aug. 2005, JOURNAL OF BIOLOGICAL CHEMISTRY, 280(32) (32), 29096 - 29106, English

  [Refereed]

  Scientific journal


• Importance of chroman ring and tyrosine phosphorylation in the subtype-specific translocation and activation of diacylglycerol kinase alpha by D-alpha-tocopherol

  R Fukunaga-Takenaka, Y Shirai, K Yagi, N Adachi, N Sakai, E Merino, Merida, I, N Saito

  Apr. 2005, GENES TO CELLS, 10(4) (4), 311 - 319, English

  [Refereed]

  Scientific journal

• 脊髄小脳変性症14型モデルマウスを用いた薬物治療法の探索

  小金丸 泉, 足立 直子, 今野 歩, 中園 葵, 関 貴弘, 上山 健彦, 酒井 規雄, 平井 宏和, 齋藤 尚亮

  日本組織細胞化学会, Sep. 2019, 日本組織細胞化学会総会・学術集会講演プログラム・予稿集, 60回, 70 - 70, Japanese


• PKCγKOパーキンソン症候群モデル βPIXリン酸化のドパミン遊離での役割

  白藤 俊彦, 上山 健彦, 吉野 健一, 足立 直子, 高橋 英之, 平松 直樹, 吾郷 由希夫, 松田 敏夫, 戸田 達史, 酒井 規雄, 齋藤 尚亮

  Dec. 2014, 臨床神経学, 54(Suppl.) (Suppl.), S242 - S242, Japanese


• A protein kinase C-gamma knockout Parkinsonian model: Involvement of Pak-Interacting Exchange Factor-beta

  Toshihiko Shirafuji, Takehiko Ueyama, Ken-ichi Yoshino, Naoko Adachi, Hideyuki Takahashi, Naoki Hiramatsu, Yukio Ago, Toshio Matsuda, Norio Sakai, Naoaki Saito

  2014, JOURNAL OF PHARMACOLOGICAL SCIENCES, 124, 207P - 207P, English

  Summary international conference


• Analysis of PKCY substrates in nigro-striatum system:The role of beta PIX phosphorylation in the dopamine release

  Toshihiko Shirafuji, Takehiko Ueyama, Kenichi Yoshino, Naoko Adachi, Hideyuki Takahashi, Yukio Ago, Toshio Matsuda, Naoaki Saito

  2013, JOURNAL OF PHARMACOLOGICAL SCIENCES, 121, 122P - 122P, English

  Summary international conference


• 黒質線条体系におけるPKCγの基質の解析

  白藤 俊彦, 上山 健彦, 吉野 健一, 足立 直子, 高橋 英之, 香田 健, 梨子田 哲明, 吾郷 由希夫, 松田 敏夫, 齋藤 尚亮

  Oct. 2012, 日本薬理学雑誌, 140(4) (4), 1P - 1P, Japanese


• PKCγノックアウトマウスを用いたパーキンソン症候群モデルの作製

  白藤 俊彦, 足立 直子, 高橋 英之, 香田 健, 梨子田 哲明, 吾郷 由希夫, 松田 敏夫, 齋藤 尚亮

  Mar. 2011, 兵庫県医師会医学雑誌, 53(2) (2), 63 - 63, Japanese


• PKCγノックアウトは黒質線条体ドパミン神経系の異常をもたらす

  白藤 俊彦, 足立 直子, 高橋 英之, 香田 健, 梨子田 哲明, 吾郷 由希夫, 松田 敏夫, 齋藤 尚亮

  Mar. 2011, 日本薬理学雑誌, 137(3) (3), 22P - 22P


• DG-PKCシグナル系の可視化とその異常による疾患

  斎藤 尚亮, 白井 康仁, 松原 岳大, 足立 直子, 高橋 英之, 酒井 規雄

  05 Jun. 2007, 脂質生化学研究, 49, 15 - 15, Japanese


• Effects of mutant gamma PKC found in SCA14 on the nature of primary cultured Purkinje cells

  Takahiro Seki, Takayuki Shimahara, Nana Abe, Kazuhiro Yamamoto, Naoko Adachi, Kaori Kashiwagi, Naoaki Saito, Norio Sakai

  2007, NEUROSCIENCE RESEARCH, 58, S118 - S118, English

  Summary international conference


• Mutant gamma PKC found in SCA14 forms cytotoxic aggregates in a microtubule-dependent manner.

  Takahiro Seki, Hideyuki Takahashi, Naoko Adachi, Naoaki Saito, Norio Sakai

  2007, JOURNAL OF PHARMACOLOGICAL SCIENCES, 103, 139P - 139P, English

  Summary international conference


• SCA14の発症機構の検討 ユビキチン-プロテアソーム系との関連

  酒井 規雄, 関 貴弘, 島原 隆行, 川上 秀史, 足立 直子, 斎藤 尚亮, 松本 昌泰

  Dec. 2006, 臨床神経学, 46(12) (12), 1111 - 1111, Japanese


• 遺伝性脊髄小脳失調症を引き起こすγPKC変異の新規同定と同定された変異γPKCの性質

  酒井 規雄, 平本 恵子, 井上 貴美子, 関 貴弘, 足立 直子, 天野 託, 川上 秀史, 松本 昌泰, 斎藤 尚亮

  (公社)日本薬理学会, Aug. 2006, 日本薬理学雑誌, 128(2) (2), 20P - 20P, Japanese


• Ubiquitin proteasome system was impaired by the aggregate formation of mutant gamma PKC found in SCA14

  Takahiro Seki, Takayuki Shimahara, Naoko Adachi, Naoaki Saito, Norio Sakai

  2006, NEUROSCIENCE RESEARCH, 55, S202 - S202, English

  Summary international conference


• Involvement of ubiquitin-proteasome system in the cytotoxic effect of mutant protein kinase C gamma found in spinocerebellar ataxia type 14

  T Seki, T Shimahara, N Adachi, H Matsubayashi, T Amano, N Saito, N Sakai

  2006, JOURNAL OF PHARMACOLOGICAL SCIENCES, 100, 240P - 240P, English

  Summary international conference


• 遺伝性脊髄小脳失調症14型(SCA14)で見いだされた変異γPKCの性質

  酒井 規雄, 関 貴弘, 足立 直子, 斎藤 尚亮, 川上 秀史, 松本 昌泰

  Dec. 2005, 臨床神経学, 45(12) (12), 1077 - 1077, Japanese


• Protein kinase C gamma (gamma PKC) mutants found in spinocerebellar ataxia (SCA) preferably aggregate in the cytoplasm

  T Seki, N Adachi, K Hiramoto, T Amano, H Matsubayashi, N Saito, N Sakai

  2005, JOURNAL OF PHARMACOLOGICAL SCIENCES, 97, 72P - 72P, English

  Summary international conference

• 脳科学辞典

  足立直子, 齋藤尚亮

  Joint work, Gタンパク質共役型受容体, Feb. 2016

  DOI

• Age-progressive circuit and axonal dysfunction induced by Purkinje cell–targeted SCA14 mutant PKCγ

  Naoko Adachi, Naoaki Saito, Takehiko Ueyama

  The 99th Annual Meeting of the Japanese Pharmacological Society, Mar. 2026, English

  [Invited]

  Invited oral presentation


• パルミトイル化修飾酵素DHHCタンパク質の新規活性測定法の開発と機能解析

  足立直子, Douglas T. Hess, 上山健彦

  第144回 日本薬理学会近畿部会, Mar. 2024, Japanese


• セロトニントランスポーターのパルミトイル化部位の解析

  原田佳奈, 山本有華, 香山怜佳, 横山英里, 髙倉大幹, 庄亮真, 足立直子, 田中茂, 秀和泉, 酒井規雄

  第142回日本薬理学会近畿部会, Nov. 2022, Japanese


• チロシナーゼのパルミトイル化修飾によるメラニン合成制御機構

  仁木洋子, 足立直子, 深田正紀, 深田優子, 錦織千佳子, 齋藤尚亮, 上山健彦

  第141回日本薬理学会 近畿部会, Jul. 2022, Japanese


• パルミトイル化がセロトニントランスポーターの成熟に与える影響

  原田佳奈, 香山怜佳, 横山英里, 髙倉大幹, 庄亮真, 足立直子, 田中茂, 秀和泉, 酒井規雄

  第142回 日本薬学会 年会, Mar. 2022, Japanese


• Global nitric oxide regulation on S-palmitoylation

  Naoko Adachi, Douglas T. Hess, Izumi Koganemaru, Takehiko Ueyama, Naoaki Saito

  The 94th Annual Meeting of the Japanese Pharmacological Society, Mar. 2021, English

  Oral presentation


• セロトニントランスポーターのS-パルミトイル化とその役割

  原田佳奈, 横山英里, 髙倉大幹, 庄亮真, 足立直子, 田中茂, 秀和泉, 酒井規雄

  第138回日本薬理学会近畿部会, Nov. 2020, Japanese


• セロトニントランスポーターのS-パルミトイル化

  原田佳奈, 横山英里, 足立直子, 田中茂, 秀和泉, 酒井規雄

  第59回日本薬学会・日本薬剤師会・日本病院薬剤師会中国四国支部学術大会, Nov. 2020


• Vitamin E induces palmitoylation of 67kDa laminin receptor by direct binding

  岡本聖香, 林大輝, 足立直子, Varnavas Mouchlis, 上田修司, 山之上稔, Edward Dennis, 伊藤俊樹, 斎藤 尚亮, 白井康仁

  第93回日本薬理学会年会, Mar. 2020, Japanese


• 脊髄小脳変性症14型モデルマウスを用いた薬物治療法の探索

  小金丸泉, 足立直子, 今野歩, 中園葵, 関貴弘, 上山健彦, 酒井規雄, 平井宏和, 齋藤尚亮

  第60回日本組織細胞化学会総会・学術集会, Sep. 2019, Japanese

  Oral presentation


• 薬剤誘導ヒートショックタンパク質は脊髄小脳変性症14型の神経細胞毒性を緩和する

  中園葵, 足立直子, 高橋英之, 関貴弘, 濵田大三, 上山健彦, 酒井規雄, 齋藤尚亮

  第60回日本組織細胞化学会総会・学術集会, Sep. 2019, Japanese

  Poster presentation


• Dynamics of chromatin structure regulating nucleotide excision repair

  Erina Kakumu, Seiya Nakanishi, Wataru Sakai, Naoko Adachi, Naoaki Saito, Hiroshi Kimura, Kaoru Sugasawa

  Conference on Responses to DNA Damage: from Molecule to Disease, Apr. 2016, English, Egmond aan Zee, The Netherlands, International conference

  Poster presentation


• ヌクレオチド除去修復を制御するクロマチン構造動態の解析

  各務恵理菜, 中西正哉, 酒井 恒, Adachi Naoko, Saito Naoaki, 田嶋正二, Sugasawa Kaoru

  第38回日本分子生物学会年会・第88回日本生化学会大会合同大会（BMB2015）, Dec. 2015, Japanese, 日本分子生物学会, 神戸, Domestic conference

  Poster presentation


• ヌクレオチド除去修復を制御するクロマチン構造動態の解析

  各務 恵理菜, 中西 正哉, 酒井 恒, ADACHI NAOKO, SAITO NAOAKI, 田嶋 正二, 菅澤 薫

  第38回日本分子生物学会年会・第88回日本生化学会大会合同大会(BMB2015), Dec. 2015, Japanese, 日本分子生物学会, 神戸, Domestic conference

  Poster presentation


• PKC KO Parkinsonian syndrome model:The role of PIX phosphorylation at Ser340 and Ser583 in dopamine release.

  Shirafuji, T, Ueyama Takehiko, Yoshino Kenichi, Adachi Naoko, Takahashi Harumi, Hiramatsu, N, Ago, Y, Matsuda, T, Toda Tatsushi, Sakai, N, Saito Naoaki

  第37回日本神経科学大会, Sep. 2014, Japanese, 日本神経科学会, 横浜, Domestic conference

  Poster presentation


• Analysis of PKC substrates in nigro-striatum system:The role of bPIX phosphorylation for dopamine release.

  Shirafuji, T, Ueyama Takehiko, Yoshino Kenichi, Adachi Naoko, Takahashi Harumi, Hiramatsu, N, Ago, Y, Matsuda, T, Toda Tatsushi, Sakai, N, Saito Naoaki

  Society for Neuroscience 2014, Sep. 2014, English, Society for Neuroscience, Washington D.C., USA, International conference

  Oral presentation


• PKCノックアウトパーキンソン症候群モデル：bPIXリン酸化のドパミン遊離での役割

  白藤俊彦, Ueyama Takehiko, Yoshino Kenichi, Adachi Naoko, 高橋英之, 香田 健, 平松直樹, 吾郷 由希夫, 松田敏夫, Toda Tatsushi, 酒井規雄, Saito Naoaki

  第55回日本神経学会学術大会, May 2014, Japanese, 日本神経学会, 福岡, Domestic conference

  Poster presentation


• Involvment of PKCgamma in neurodegenerative disease

  Saito Naoaki, Takahashi Harumi, Shirafuji T, Adachi Naoko, Danno S, Ueyama Takehiko, Seki Tsuneyoshi, Sakai N

  ICHC2012, Aug. 2012, English, 国際組織細胞化学会, 京都, International conference

  Public symposium


• 黒質線条体系におけるPKCgammaの基質の解析

  白藤 俊彦, Yoshino Kenichi, Adachi Naoko, 高橋 英之, 香田 健, 梨子田 哲明, 吾郷 由希夫, 松田 敏夫, Saito Naoaki

  第121回日本薬理学会近畿部会, Mar. 2012, Japanese, 日本薬理学会, 徳島, Domestic conference

  Oral presentation

• 活性酸素産生酵素NOX3の発現制御機序解明による後天性及び片側性難聴の治療法開発

  上山 健彦, 坂口 博史, 足立 直子, 中村 高志

  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 01 Apr. 2024 - 31 Mar. 2027


• 一酸化窒素によるS-パルミトイル化修飾酵素抑制機構の解明

  足立 直子

  日本学術振興会, 科学研究費助成事業, 基盤研究(C), 神戸大学, 01 Apr. 2022 - 31 Mar. 2025


• Nox3由来ROSによる難聴（加齢、騒音、薬剤、突発性）の発症機序解明とその先へ

  上山 健彦, 坂口 博史, 足立 直子, 中村 高志

  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 01 Apr. 2021 - 31 Mar. 2024

  1. 自ら開発したNADPH oxidase 3 (Nox3) 発現細胞が赤色蛍光蛋白 tdTomato で標識される（Nox3-CreKI;tdTomato+/+）マウスを用い、耳石形成に必須のNox3由来活性酸素（ROS）発生源細胞として、内リンパ嚢・内リンパ管の管腔に面した上皮細胞を特定した。更に、Nox3が一次聴覚感受器官である蝸牛コルチ器に発現することを発見、Nox3発現細胞として、内・外有毛細胞とその周囲に存在し有毛細胞を機能・構造的に支える種々の支持細胞（内・外指節細胞、外柱細胞、クラウディウス細胞）を特定した。 2. 加えて、上記の蝸牛におけるNox3発現（tdTomato陽性）細胞数が、聴毒性で有名な抗癌剤であるシスプラチンの投与および加齢や騒音不可により上昇する事を発見した。特に、Nox3が発現誘導された外有毛細胞は、アポトーシスに陥ることを明らかにした。 3.自ら開発したNox3-knockout (KO)マウスを用いて、シスプラチン誘発感音難聴、加齢性感音難聴、騒音性感音難聴において、Nox3-KOが聴覚温存に働くことを明らかにした。 4.上記3種の主要後天性感音難聴の中で、シスプラチン誘発感音難聴と加齢性感音難聴においてNox3の関与が非常に高く、騒音性感音難聴ではやや低いが有意に関与することを明らかにした。
  上記の結果は、Nox3の蝸牛コルチ器（特に、外有毛細胞細胞）での発現抑制が、後天性感音難聴の治療法開発の標的になる事を強く示唆している。


• 脊髄小脳変性症におけるアミロイド様線維形成機構の解明と治療法の開発

  齋藤 尚亮

  科学研究費補助金／基盤研究(B), Apr. 2017 - Mar. 2020

  Competitive research funding


• 遺伝子多型を有するヒト化β３アドレナリン受容体マウスの作製と関連疾患の解明

  足立 直子

  学術研究助成基金助成金／基盤研究(C), Apr. 2017 - Mar. 2020, Principal investigator

  Competitive research funding


• β3アドレナリン受容体遺伝子多型が肥満・過活動膀胱に及ぼす影響と治療法の探索（国際共同研究強化）

  足立 直子

  日本学術振興会, 学術研究助成基金助成金／国際共同研究加速基金(国際共同研究強化), 国際共同研究加速基金（国際共同研究強化）, 神戸大学, Apr. 2017 - Mar. 2020, Principal investigator

  Competitive research funding


• パルミトイル化によるβ３アドレナリン受容体の脱感作と脂肪分解促進メカニズムの解明

  足立 直子

  学術研究助成基金助成金／若手研究(B), Apr. 2015 - Mar. 2017, Principal investigator

  Competitive research funding


• 神経変性疾患発症に関与するＰＫＣリン酸化基質タンパク質の同定と創薬への応用

  齋藤 尚亮

  科学研究費一部基金／基盤研究(B)特設, Apr. 2013 - Mar. 2016

  Competitive research funding


• システイン翻訳後修飾がＧＰＣＲ機能調節に与える影響の検討

  足立 直子

  科学研究費補助金／若手研究(B), Apr. 2012 - Mar. 2014, Principal investigator

  Competitive research funding


• タンパク質のニトロシル化とパルミトイル化修飾の相互制御システムの解析

  足立 直子

  科学研究費補助金／若手研究(スタートアップ), 2011, Principal investigator

  Competitive research funding


• 脊髄小脳変性症モデルマウスの作製と発症メカニズムの分子生物学的・病理学的解析

  足立 直子

  日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 神戸大学, 2007 - 2008

  SCA14変異型PKCγ発現細胞においてPKCγの機能不全により受容体刺激後のカルシウムの流入量が増大し、細胞内のカルシウムホメオスタシスを変化させていることが判明した。このカルシウムの流入にはTRPC3チャネルの関与が強く示唆された。野生型PKCγはTRPC3チャネルをリン酸化することによりTRPC3チャネルを介したカルシウムの流入阻害するのに対して、変異型PKCγではTRPC3チャネルをリン酸化することが出来なくなってしいた。これは、SCA14の変異によりPKCγのC1ドメインと細胞膜脂質ジアシルグリセロールとの結合能が低下し、細胞質膜上に安定的に滞在出来ず、変異型PKCγが細胞質膜上のTRPC3チャネルと相互作用出来なくなったためだと考えられた。 一方で、我々はSCA14変異体のうち、G128DとG360SについてCre/LoxPシステムを用いて、部位特異的に変異タンパク質の発現を調節できる病態モデルマウスを作製している。既に、小脳プルキンエ細胞での変異タンパク質の発現は確認しており、これらのマウスにおいて小脳脊髄変性症様の病態の有無を観察中である。これまでのところ、変異タンパク質の発現量が内在性のPKCγと比較して少ないこともあり、顕著な歩行障害等は観察されていない。しかしながら、脊髄小脳変性症はヒトにおいては長期的に進行し、発症年齢にも開きがあるため、これらのマウスにおいて長期的な経過観察が必要であると考えている。