The role of heme-binding, phosphorylation, and degradation in heme-regulated eukaryotic initiation factor 2α kinase (HRI)
Project/Area Number |
21770130
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Single-year Grants |
Research Field |
Functional biochemistry
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Research Institution | Tohoku University |
Principal Investigator |
IGARASHI Jotaro Tohoku University, 多元物質科学研究所, 助教 (80375162)
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Project Period (FY) |
2009 – 2010
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Project Status |
Completed (Fiscal Year 2010)
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Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2010: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2009: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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Keywords | ヘム / 自己リン酸化 / プロテアソーム / 結晶化 / ヘム調節インヒビター / 翻訳開始因子キナーゼ / 脱リン酸化 / ヘム制御モチーフ / 質量分析 |
Research Abstract |
Heme-regulated eukaryotic initiation factor 2α (eIF2α) kinase (HRI), functions in response to heme concentration. Under normal conditions, heme binds to HRI and blocks its function. However, during heme shortage, heme dissociates from the protein, and autophosphorylation subsequently occurs. The molecular mechanism of heme-binding, autophosphorylation, and degradation in HRI remained to be established. In the present study, 1) we demonstrate that His119/His120 and Cys411 are the axial ligands for heme in human HRI, as well as mouse HRI. 2) With the aid of mass spectroscopy we identified 33 phosphorylated sites in mouse HRI overexpressed in Escherichia coli. We further generated 30 enzymes with mutations at the phosphorylated residues and examined the catalytic activities. The activities of Y193F, T485A, and T490A mutants were significantly lower than that of wild-type protein. Accordingly, we suggest that Tyr193, Thr485, and Thr490 are essential residues in the catalysis. 3) Due to degradation of HRI in cultured cell, we show that HRI degradation is induced by 20S proteasome in vitro.
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Report
(3 results)
Research Products
(37 results)
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[Journal Article] Autophosphorylation of heme-regulated eukaryotic initiation factor 2α kinase, HRI, and the role of the modification in catalysis.2011
Author(s)
Igarashi, J., Sasaki, T., Kobayashi, N., Yoshioka, S., Matsushita, M., Shimizu, T.
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Journal Title
FEBS J. 278
Pages: 918-928
Related Report
Peer Reviewed
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[Journal Article] Catalysis and oxygen binding of Ec DOS, a heme-based oxygen-sensor enzyme from Escherichia coli.2010
Author(s)
Kobayashi, K., Tanaka, A., Takahashi, H., Igarashi, J., Ishitsuka, Y., Yokota, N., Shimizu, T.
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Journal Title
J.Biochem. 148
Pages: 693-703
Related Report
Peer Reviewed
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[Journal Article] Important roles of Tyr43 at the putative heme distal side in oxygen recognition and stability of the Fe(II)-O 2 complex of YddV, a globin-coupled heme-based oxygen sensor diguanylate cyclase.2010
Author(s)
Kitanishi, K., Kobayashi, K., Kawamura, Y., Ishigami, I., Ogura, T., Nakajima, K., Igarashi, J., Tanaka, A., Shimizu, T.
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Journal Title
Biochemistry 49
Pages: 10381-10393
Related Report
Peer Reviewed
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[Journal Article] Selective neuronal nitric oxide synthase inhibitors and the prevention of cerebral palsy.2009
Author(s)
Ji, H., Tan, S., Igarashi, J., Li, H., Derrick, M., Martasek, P., Roman, L., Vasquez-Vivar, J., Poulos, T.L., Silverman, R.B.
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Journal Title
Ann.Neurol. 65
Pages: 209-217
Related Report
Peer Reviewed
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[Journal Article] Role of Phe113 at the distal side of the heme domain of an oxygen-sensor (Ec DOS) in the characterization of the heme environment.2009
Author(s)
Ito, S., Araki, Y., Tanaka, A., Igarashi, J., Wada, T., Shimizu, T.
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Journal Title
J.Inorg.Biochem. 103
Pages: 989-996
Related Report
Peer Reviewed
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[Journal Article] Crystal structures of constitutive nitric oxide synthases in complex with de novo designed inhibitors.2009
Author(s)
Igarashi, J., Li, H., Jamal, J., Ji, H., Fang, J., Lawton, G., Silverman, R.B., Poulos, T.L.
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Journal Title
J.Med.Chem. 52
Pages: 2060-2066
Related Report
Peer Reviewed
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[Presentation] NO-induced activation of a heme-sensor, eIF2α kinase, in association with binding to cysteine and heme.2010
Author(s)
Igarashi, J., Sasaki, T., Iwashita, J.,Shimizu, T.
Organizer
6th International Conference, Biology, Chemistry, and Therapeutic Applications of Nitric Oxide.
Place of Presentation
Kyoto,Japan.
Year and Date
2010-06-15
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[Presentation] The heme-binding site of the heme-regulated inhibitor (HRI), and the role of heme regulatory motif in heme sensing.2009
Author(s)
Igarashi, J.,Murase, M., Shimizu, T.
Organizer
16th International Conference on Cytochrome P450, Biochemisty, Biphysics, Functional Genomics.
Place of Presentation
Nago, Japan.
Year and Date
2009-06-23
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[Book] Emerging Role of Heme as a Signal and the Gas-Sensing Site : Heme-Sensing and Gas-Sensing Proteins.Handbook of Porphyrin Science (Kadish, K.M., Smith, K.M., Guilard, R.Eds.)2011
Author(s)
Igarashi, J., Kitanishi, K., Shimizu, T.
Publisher
World Scientific (Hackensack, NJ, USA)
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