研究者業績

椎葉 一心

シイバ イッシン  (Isshin Shiiba)

基本情報

所属
学習院大学 理学部 生命分子科学研究所 助教
東京薬科大学 客員研究員
学位
博士 (生命科学)

研究者番号
30884481
ORCID ID
 https://orcid.org/0000-0002-8093-1782
J-GLOBAL ID
202001009829771490
researchmap会員ID
R000003180

論文

 12
  • Shun Nagashima, Naoki Ito, Isshin Shiiba, Hiroki Shimura, Shigeru Yanagi
    The Journal of Biochemistry 2022年11月8日  
    Abstract Mitochondria are involved in various cellular processes, such as energy production, inflammatory responses, and cell death. Mitochondrial dysfunction is associated with many age-related diseases, including neurological disorders and heart failure. Mitochondrial quality is strictly maintained by mitochondrial dynamics linked to an adequate supply of phospholipids and other substances from the endoplasmic reticulum (ER). The outer mitochondrial membrane-localized E3 ubiquitin ligase MITOL/MARCHF5 is responsible for mitochondrial quality control through the regulation of mitochondrial dynamics, formation of mitochondria-ER contacts, and mitophagy. MITOL deficiency has been shown to impair mitochondrial function, cause an excessive inflammatory response, and increase vulnerability to stress, resulting in the exacerbation of the disease. In this study, we overview the ubiquitin-mediated regulation of mitochondrial function by MITOL and the relationship between MITOL and diseases.
  • Takeshi Tokuyama, Hideki Uosaki, Ayumu Sugiura, Gen Nishitai, Keisuke Takeda, Shun Nagashima, Isshin Shiiba, Naoki Ito, Taku Amo, Satoshi Mohri, Akiyuki Nishimura, Motohiro Nishida, Ayumu Konno, Hirokazu Hirai, Satoshi Ishido, Takahiro, Yoshizawa, Takayuki Shindo, Shingo Takada, Shintaro Kinugawa, Ryoko Inatome, Shigeru Yanagi
    iScience 25(7) 104582-104582 2022年  
    Abnormal mitochondrial fragmentation by dynamin-related protein1 (Drp1) is associated with the progression of aging-associated heart diseases, including heart failure and myocardial infarction (MI). Here, we report a protective role of outer mitochondrial membrane (OMM)-localized E3 ubiquitin ligase MITOL/MARCH5 against cardiac senescence and MI, partly through Drp1 clearance by OMM-associated degradation (OMMAD). Persistent Drp1 accumulation in cardiomyocyte-specific MITOL conditional-knockout mice induced mitochondrial fragmentation and dysfunction, including reduced ATP production and increased ROS generation, ultimately leading to myocardial senescence and chronic heart failure. Furthermore, ischemic stress-induced acute downregulation of MITOL, which permitted mitochondrial accumulation of Drp1, resulted in mitochondrial fragmentation. Adeno-associated virus-mediated delivery of the MITOL gene to cardiomyocytes ameliorated cardiac dysfunction induced by MI. Our findings suggest that OMMAD activation by MITOL can be a therapeutic target for aging-associated heart diseases, including heart failure and MI.
  • Naoki Ito, Takara Takahashi, Isshin Shiiba, Shun Nagashima, Ryoko Inatome, Shigeru Yanagi
    Journal of biochemistry 171(5) 529-541 2021年12月29日  
    The transfer of phospholipids from the endoplasmic reticulum to mitochondria via the mitochondria-endoplasmic reticulum (ER) contact site (MERCS) is essential for maintaining mitochondrial function and integrity. Here, we identified RMDN3/PTPIP51, possessing phosphatidic acid (PA)-transfer activity, as a neighboring protein of the mitochondrial E3 ubiquitin ligase MITOL/MARCH5 by proximity-dependent biotin labeling using APEX2. We found that MITOL interacts with and ubiquitinates RMDN3. Mutational analysis identified lysine residue 89 in RMDN3 as a site of ubiquitination by MITOL. Loss of MITOL or the substitution of lysine 89 to arginine in RMDN3 significantly reduced the PA-binding activity of RMDN3, suggesting that MITOL regulates the transport of PA to mitochondria by activating RMDN3. Our findings imply that ubiquitin signaling regulates phospholipid transport at the MERCS.
  • Shun Nagashima, Naoki Ito, Reiki Kobayashi, Isshin Shiiba, Hiroki Shimura, Toshifumi Fukuda, Hideo Hagihara, Tsuyoshi Miyakawa, Ryoko Inatome, Shigeru Yanagi
    The Journal of biological chemistry 100620-100620 2021年3月31日  
    Mouse models of various neuropsychiatric disorders, such as schizophrenia, often display an immature dentate gyrus, characterized by increased numbers of immature neurons and neuronal progenitors and a dearth of mature neurons. We previously demonstrated that the CRMP5-associated GTPase (CRAG), a short splice variant of Centaurin-γ3/AGAP3, is highly expressed in the dentate gyrus. CRAG promotes cell survival and antioxidant defense by inducing the activation of serum response factors at promyelocytic leukemia protein bodies, which are nuclear stress-responsive domains, during neuronal development. However, the physiological role of CRAG in neuronal development remains unknown. Here, we analyzed the role of CRAG using dorsal forebrain-specific CRAG/Centaurin-γ3 knockout mice. The mice revealed maturational abnormality of the hippocampal granule cells, including increased doublecortin-positive immature neurons and decreased calbindin-positive mature neurons, a typical phenotype of immature dentate gyri. Furthermore, the mice displayed hyperactivity in the open-field test, a common measure of exploratory behavior, suggesting that these mice may serve as a novel model for neuropsychiatric disorder associated with hyperactivity. Thus, we conclude that CRAG is required for the maturation of neurons in the dentate gyrus, raising the possibility that its deficiency might promote the development of psychiatric disorders in humans.
  • Isshin Shiiba, Keisuke Takeda, Shun Nagashima, Naoki Ito, Takeshi Tokuyama, Shun-Ichi Yamashita, Tomotake Kanki, Toru Komatsu, Yasuteru Urano, Yuuta Fujikawa, Ryoko Inatome, Shigeru Yanagi
    EMBO reports 22(3) e49097 2021年3月3日  
    Parkin promotes cell survival by removing damaged mitochondria via mitophagy. However, although some studies have suggested that Parkin induces cell death, the regulatory mechanism underlying the dual role of Parkin remains unknown. Herein, we report that mitochondrial ubiquitin ligase (MITOL/MARCH5) regulates Parkin-mediated cell death through the FKBP38-dependent dynamic translocation from the mitochondria to the ER during mitophagy. Mechanistically, MITOL mediates ubiquitination of Parkin at lysine 220 residue, which promotes its proteasomal degradation, and thereby fine-tunes mitophagy by controlling the quantity of Parkin. Deletion of MITOL leads to accumulation of the phosphorylated active form of Parkin in the ER, resulting in FKBP38 degradation and enhanced cell death. Thus, we have shown that MITOL blocks Parkin-induced cell death, at least partially, by protecting FKBP38 from Parkin. Our findings unveil the regulation of the dual function of Parkin and provide a novel perspective on the pathogenesis of PD.

MISC

 30

書籍等出版物

 1

講演・口頭発表等

 6

共同研究・競争的資金等の研究課題

 3