RACK1A promotes hypocotyl elongation by scaffolding light signaling components in Arabidopsis  

作　　者：Yajuan Fu Wei Zhu Yeling Zhou Yujing Su Zhiyong Li Dayan Zhang Dong Zhang Jinyu Shen Jiansheng Liang 

机构地区：[1]Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes,Department of Biology,School of Life Sciences,Institute of Plant and Food Sciences,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Journal of Integrative Plant Biology》2024年第5期956-972,共17页植物学报（英文版）

基　　金：supported by grants from National Natural Science Foundation of China(32070292 to J.L.);Shenzhen Science and Technology Program(KQTD20190929173906742 to J.L.);The Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes(2019KSYS006 to J.L.);Scientific Research Funding for postdoctoral researchers staying at Shenzhen(K19227561,K21227504 to W.Z.).

摘　　要：Plants deploy versatile scaffold proteins to intricately modulate complex cell signaling.Among these,RACK1A(Receptors for Activated C Kinase 1A)stands out as a multifaceted scaffold protein functioning as a central integrative hub for diverse signaling pathways.However,the precise mechanisms by which RACK1A orchestrates signal transduction to optimize seedling development remain largely unclear.Here,we demonstrate that RACK1A facilitates hypocotyl elongation by functioning as a flexible platform that connects multiple key components of light signaling pathways.RACK1A interacts with PHYTOCHROME INTERACTING FACTOR(PIF)3,enhances PIF3 binding to the promoter of BBX11 and down-regulates its transcription.Furthermore,RACK1A associates with ELONGATED HYPOCOTYL 5(HY5)to repress HY5 biochemical activity toward target genes,ultimately contributing to hypocotyl elongation.In darkness,RACK1A is targeted by CONSTITUTIVELY PHOTOMORPHOGENIC(COP)1 upon phosphorylation and subjected to COP1-mediated degradation via the 26 S proteasome system.Our findings provide new insights into how plants utilize scaffold proteins to regulate hypocotyl elongation,ensuring proper skoto-and photo-morphogenic development.

关 键 词：ARABIDOPSIS hypocotyl development light signaling components RACK1 scaffoldprotein 

分 类 号：Q945[生物学—植物学]