title: Plastid-nucleus communication involves calcium-modulated MAPK signalling.
abstract: Chloroplast retrograde signals play important roles in coordinating the plastid and nuclear gene expression and are critical for proper chloroplast biogenesis and for maintaining optimal chloroplast functions in response to environmental changes in plants. Until now, the signals and the mechanisms for retrograde signalling remain poorly understood. Here we identify factors that allow the nucleus to perceive stress conditions in the chloroplast and to respond accordingly by inducing or repressing specific nuclear genes encoding plastid proteins. We show that ABI4, which is known to repress the LHCB genes during retrograde signalling, is activated through phosphorylation by the MAP kinases MPK3/MPK6 and the activity of these kinases is regulated through 14-3-3ω-mediated Ca(2+)-dependent scaffolding depending on the chloroplast calcium sensor protein CAS. These findings uncover an additional mechanism in which chloroplast-modulated Ca(2+) signalling controls the MAPK pathway for the activation of critical components of the retrograde signalling chain.
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hailong
authors.initials: H
authors.lastname: Guo
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Peiqiang
authors.initials: P
authors.lastname: Feng
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chi
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xuwu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
authors.forename: Dongtao
authors.initials: D
authors.lastname: Ren
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Congming
authors.initials: C
authors.lastname: Lu
authors.affiliation: Departments of Molecular Biology and Plant Biology, University of Geneva, 1211 Geneva, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: David Rochaix
authors.affiliation: Division of Plant Molecular Biology (Botany), Department Biology I, Ludwig Maximilians University, 80638 Munich, Germany.
authors.forename: Dario
authors.initials: D
authors.lastname: Leister
authors.affiliation: Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D048948:14-3-3 Proteins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism*; D020013:Calcium Signaling; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D060365:Chloroplast Proteins / Q000235:genetics*; D002736:Chloroplasts / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D045342:Light-Harvesting Protein Complexes / Q000235:genetics*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D001678:Organelle Biogenesis; D030821:Plants, Genetically Modified; D018087:Plastids / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; C513203:14-3-3omega protein, Arabidopsis; C470421:ABI4 protein, Arabidopsis; D029681:Arabidopsis Proteins; C532740:CAS protein, Arabidopsis; D002135:Calcium-Binding Proteins; D060365:Chloroplast Proteins; D045342:Light-Harvesting Protein Complexes; D014157:Transcription Factors; C458516:AtMPK3 protein, Arabidopsis; C436293:MPK6 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases