1. Cell Biology
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EDEM2 stably disulfide-bonded to TXNDC11 catalyzes the first mannose trimming step in mammalian glycoprotein ERAD

  1. Ginto George
  2. Satoshi Ninagawa
  3. Hirokazu Yagi
  4. Taiki Saito
  5. Tokiro Ishikawa
  6. Tetsushi Sakuma
  7. Takashi Yamamoto
  8. Koshi Imami
  9. Yasushi Ishihama
  10. Koichi Kato
  11. Tetsuya Okada  Is a corresponding author
  12. Kazutoshi Mori  Is a corresponding author
  1. Kyoto University, Japan
  2. Nagoya City University, Japan
  3. Hiroshima University, Japan
Research Article
  • Cited 2
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Cite this article as: eLife 2020;9:e53455 doi: 10.7554/eLife.53455

Abstract

Sequential mannose trimming of N-glycan (Man9GlcNAc2 -> Man8GlcNAc2 -> Man7GlcNAc2) facilitates endoplasmic reticulum-associated degradation of misfolded glycoproteins (gpERAD). Our gene knockout experiments in human HCT116 cells have revealed that EDEM2 is required for the first step. However, it was previously shown that purified EDEM2 exhibited no a1,2-mannosidase activity toward Man9GlcNAc2 in vitro. Here, we found that EDEM2 was stably disulfide-bonded to TXNDC11, an endoplasmic reticulum protein containing five thioredoxin (Trx)-like domains. C558 present outside of the mannosidase homology domain of EDEM2 was linked to C692 in Trx5, which solely contains the CXXC motif in TXNDC11. This covalent bonding was essential for mannose trimming and subsequent gpERAD in HCT116 cells. Furthermore, EDEM2-TXNDC11 complex purified from transfected HCT116 cells converted Man9GlcNAc2 to Man8GlcNAc2(isomerB) in vitro. Our results establish the role of EDEM2 as an initiator of gpERAD, and represent the first clear demonstration of in vitro mannosidase activity of EDEM family proteins.

Article and author information

Author details

  1. Ginto George

    Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  2. Satoshi Ninagawa

    Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  3. Hirokazu Yagi

    Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9296-0225
  4. Taiki Saito

    Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
    Competing interests
    The authors declare that no competing interests exist.
  5. Tokiro Ishikawa

    Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1718-6764
  6. Tetsushi Sakuma

    Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0396-1563
  7. Takashi Yamamoto

    Department of Mathematical and Life Sciences, Hiroshima University, Hiroshima, Japan
    Competing interests
    The authors declare that no competing interests exist.
  8. Koshi Imami

    Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  9. Yasushi Ishihama

    Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  10. Koichi Kato

    Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
    Competing interests
    The authors declare that no competing interests exist.
  11. Tetsuya Okada

    Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
    For correspondence
    tokada@upr.biophys.kyoto-u.ac.jp
    Competing interests
    The authors declare that no competing interests exist.
  12. Kazutoshi Mori

    Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
    For correspondence
    mori@upr.biophys.kyoto-u.ac.jp
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7378-4019

Funding

Ministry of Education, Culture, Sports, Science, and Technology (18K06216)

  • Satoshi Ninagawa

Ministry of Education, Culture, Sports, Science, and Technology (17H06414)

  • Hirokazu Yagi

Ministry of Education, Culture, Sports, Science, and Technology (19K06658)

  • Tokiro Ishikawa

Ministry of Education, Culture, Sports, Science, and Technology (18K06110)

  • Tetsuya Okada

Ministry of Education, Culture, Sports, Science, and Technology (17H01432)

  • Kazutoshi Mori

Ministry of Education, Culture, Sports, Science, and Technology (17H06419)

  • Kazutoshi Mori

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Adam Linstedt, Carnegie Mellon University, United States

Publication history

  1. Received: November 8, 2019
  2. Accepted: February 7, 2020
  3. Accepted Manuscript published: February 17, 2020 (version 1)
  4. Version of Record published: February 24, 2020 (version 2)

Copyright

© 2020, George et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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