α1-COP modulates plasmodesmata function through sphingolipid enzyme regulation  

作　　者：Arya Bagus Boedi Iswanto Minh Huy Vu Jong Cheol Shon Ritesh Kumar Shuwei Wu Hobin Kang Da-Ran Kim Geon Hui Son Woe Yoen Kim Youn-Sig Kwak Kwang Hyeon Liu Sang Hee Kim Jae-Yean Kim 

机构地区：[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

出　　处：《Journal of Integrative Plant Biology》2024年第8期1639-1657,共19页植物学报（英文版）

基　　金：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);a grant from the New Breeding Technologies Development Program(Grant No.PJ01653202),Rural Development Administration(RDA),Republic of Korea。

摘　　要：Callose,aβ-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 wasα1-COP,a member of the coat protein I(COPI)coatomer complex.We report that loss of function ofα1-COP elevates the callose accumulation at PD by affecting subcellular protein localization of callose degradation enzyme Pd BG2.This process is linked to the functions of ERH1,an inositol phosphoryl ceramide synthase,and glucosylceramide synthase through physical interactions with theα1-COP protein.Additionally,the loss of function ofα1-COP alters the subcellular localization of ERH1 and GCS proteins,resulting in a reduction of Glc Cers and Glc HCers molecules,which are key sphingolipid(SL)species for lipid raft formation.Our findings suggest thatα1-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.

关 键 词：CALLOSE coatomer proteins membrane-bound vesicle PLASMODESMATA sphingolipid enzymes 

分 类 号：Q942[生物学—植物学]