he BCM1-EGY1 module balances chlorophyll biosynthesis and breakdown to confer chlorophyll homeostasis in land plants  

作　　者：Dali Fu Hanlin Zhou Bernhard Grimm Peng Wang 

机构地区：[1]School of Biological Sciences,The University of Hong Kong,Hong Kong SAR 999077,China [2]Institute of Biology/Plant Physiology,Humboldt-Universität zu Berlin,Philippstrasse13,Building 12,10115 Berlin,Germany [3]State Key Laboratory of Agrobiotechnology,The Chinese University of Hong Kong,Hong Kong SAR 999077,China

出　　处：《Molecular Plant》2025年第1期76-94,共19页分子植物(英文版)

基　　金：supported by funds from the Deutsche Forschungsgemeinschaft(FOR2092,GR 936/18-1,SFB TRR175,subproject C04,and WA 4599/2-2);the National Natural Science Foundation of China(Excellent Young Scientists Fund for Hong Kong and Macao,32322089);the Research Grant Council of Hong Kong(Early Career Scheme,27118022;and General Research Fund,17107223);the State Key Laboratory of Agrobiotechnology at the Chinese University of Hong Kong(the ITC Funding);the University of Hong Kong(the Seed Fund for Basic Research,66620211115918 and the Startup fund);Any opinions,findings,conclusions,or recommendations expressed in this publication do not reflect the views of the Government of the Hong Kong Special Administrative Region or the Innovation and Technology Commission.

摘　　要：Chlorophyll metabolism has evolved during plant evolution.The strictly light-dependent nature of chlorophyll biosynthesis found in angiosperms requires tight coordination of chlorophyll biosynthesis and breakdown to achieve chlorophyll homeostasis.However,the specific control mechanisms remain largely unclear.Here,we demonstrate that the scaffold protein BALANCE OF CHLOROPHYLL METABOLISM1(BCM1)has co-evolved with the carboxy-terminal domains of specific enzymes involved in chlorophyll biosynthesis and breakdown,including GENOMES UNCOUPLED 4(GUN4)and Mg-dechelatase 1(SGR1).We found that the land plant-specific interaction of BCM1 with the carboxy-terminal domains of GUN4 and SGR1 is indispensable for concurrent stimulation of chlorophyll biosynthesis and suppression of chlorophyll breakdown.The land plant-specific carboxy-terminal domain is essential for the membrane docking and turnover of GUN4,whereas it is key for proteolysis of SGR1.More importantly,we identified the metallopeptidase Gravitropism-deficient and Yellow-green 1(EGY1)as the proteolytic machinery responsible for BCM1-mediated proteolysis of SGR1.In summary,this study reveals the BCM1-EGY1 module has evolved to maintain chlorophyll homeostasis by the post-translational control of the balance between chlorophyll biosynthesis and breakdown.This mechanism thus represents an evolutionary response to the metabolic demands imposed on plants in terrestrial environments.

关 键 词：chlorophyll homeostasis scaffold protein BCM1 proteolytic machinery EGY1 post-translational control 

分 类 号：G63[文化科学—教育学]