J Integr Plant Biol ›› 2024, Vol. 66 ›› Issue (8): 1639-1657.DOI: 10.1111/jipb.13711

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  • 收稿日期:2023-09-27 接受日期:2024-04-30 出版日期:2024-08-01 发布日期:2024-08-19

α1-COP modulates plasmodesmata function through sphingolipid enzyme regulation

Arya Bagus Boedi Iswanto1, Minh Huy Vu1, Jong Cheol Shon2, Ritesh Kumar1,†, Shuwei Wu1, Hobin Kang1, Da-Ran Kim3, Geon Hui Son1, Woe Yoen Kim1, Youn-Sig Kwak3, Kwang Hyeon Liu2, Sang Hee Kim1,4* and Jae-Yean Kim1,4*   

  1. 1. Division of Applied Life Science (BK21 FOUR Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea;
    2. College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu 702-701, Korea;
    3. Departement of Plant Medicine, Gyeongsang National University, Jinju 52828, Korea;
    4. Division of Life Science, Gyeongsang National University, Jinju 52828, Korea
    Present address: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, USA
    *Correspondences: Sang Hee Kim (sangheekim@gnu.ac.kr); Jae-Yean Kim (kimjy@gnu.ac.kr; Dr. Jae-Yean Kim is fully responsible for the distribution of all materials associated with this article)
  • Received:2023-09-27 Accepted:2024-04-30 Online:2024-08-01 Published:2024-08-19
  • Supported by:
    This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (Grant Nos. NRF 2018R1A2A1A05077295, 2020M3A9I4038352, 2022R1A2C3010331, 2020R1A6A1A03044344, and 2022R1A 5A1031361), and by a grant from the New Breeding Technologies Development Program (Grant No. PJ01653202), Rural Development Administration (RDA), Republic of Korea.

Abstract: Callose, a β-1,3-glucan plant cell wall polymer, regulates symplasmic channel size at plasmodesmata (PD) and plays a crucial role in a variety of plant processes. However, elucidating the molecular mechanism of PD callose homeostasis is limited. We screened and identified an Arabidopsis mutant plant with excessive callose deposition at PD and found that the mutated gene was α1-COP, a member of the coat protein I (COPI) coatomer complex. We report that loss of function of α1-COP elevates the callose accumulation at PD by affecting subcellular protein localization of callose degradation enzyme PdBG2. This process is linked to the functions of ERH1, an inositol phosphoryl ceramide synthase, and glucosylceramide synthase through physical interactions with the α1-COP protein. Additionally, the loss of function of α1-COP alters the subcellular localization of ERH1 and GCS proteins, resulting in a reduction of GlcCers and GlcHCers molecules, which are key sphingolipid (SL) species for lipid raft formation. Our findings suggest that α1- COP protein, together with SL modifiers controlling lipid raft compositions, regulates the subcellular localization of GPI-anchored PDBG2 proteins, and hence the callose turnover at PD and symplasmic movement of biomolecules. Our findings provide the first key clue to link the COPI-mediated intracellular trafficking pathway to the callose-mediated intercellular signaling pathway through PD.

Key words: callose, coatomer proteins, membrane-bound vesicle, plasmodesmata, sphingolipid enzymes

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