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A permease‐like protein involved in ER to thylakoid lipid transfer in Arabidopsis
Author(s) -
Xu Changcheng,
Fan Jilian,
Riekhof Wayne,
Froehlich John E.,
Benning Christoph
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg234
Subject(s) - thylakoid , biology , arabidopsis , endoplasmic reticulum , permease , biochemistry , plant lipid transfer proteins , twin arginine translocation pathway , mutant , arabidopsis thaliana , plastid , membrane protein , microbiology and biotechnology , chloroplast , membrane , gene
In eukaryotes, enzymes of different subcellular compartments participate in the assembly of membrane lipids. As a consequence, interorganelle lipid transfer is extensive in growing cells. A prominent example is the transfer of membrane lipid precursors between the endoplasmic reticulum (ER) and the photosynthetic thylakoid membranes in plants. Mono‐ and digalactolipids are typical photosynthetic membrane lipids. In Arabidopsis , they are derived from one of two pathways, either synthesized de novo in the plastid, or precursors are imported from the ER, giving rise to distinct molecular species. Employing a high‐throughput robotic screening procedure generating arrays of spot chromatograms, mutants of Arabidopsis were isolated, which accumulated unusual trigalactolipids. In one allelic mutant subclass, trigalactosyldiacylglycerol1 , the primary defect caused a disruption in the biosynthesis of ER‐derived thylakoid lipids. Secondarily, a processive galactosyltransferase was activated, leading to the accumulation of oligogalactolipids. Mutations in a permease‐like protein of the outer chloroplastic envelope are responsible for the primary biochemical defect. It is proposed that this protein is part of a lipid transfer complex.