Loss of the Atypical Kinases ABC1K7 and ABC1K8 Changes the Lipid Composition of the Chloroplast Membrane.
The activity of bc1 complex kinase (ABC1K) family is a large group of atypical protein kinases found in prokaryotes and eukaryotes. In bacteria and mitochondria, ABC1K kinases are necessary for the synthesis of coenzyme Q and are therefore involved in the respiratory pathway. In chloroplasts, they are involved in prenylquinone synthesis and stress responses, but their functional role remains unclear. Plants can respond to biotic and abiotic stress by modifying membrane fluidity in order to create a suitable environment for the activity of integral membrane proteins. Therefore, this work was focused on the analysis of the effect of ABC1K7 and ABC1K8 on the production of polar lipids and their accumulation in Arabidopsis thaliana leaves. A comparison of abc1k7 and abc1k8 single mutants and the abc1k7/abc1k8 double mutant with wild-type plants and transgenic lines overexpressing ABC1K7 and ABC1K8 was performed using untargeted lipidomic analysis based on liquid chromatography coupled to mass spectrometry. Multivariate data analysis identified sets of chloroplast lipids representing the different genotypes. The abc1k7 and abc1k8 single mutants produced lower levels of the highly unsaturated lipid digalactosyldiacylglycerol (DGDG) than wild-type plants and also different forms of monogalactosyldiacylglycerol (MGDG) and kaempferol. The abc1k8 mutant also produced higher levels of oxylipin-conjugated DGDG and sinapates. The double mutant produced even higher levels of oxylipin-conjugated MGDG and DGDG. These results show that ABC1K7 and ABC1K8 influence chloroplast lipid synthesis or accumulation and modulate chloroplast membrane composition in response to stress.
['Manara|Anna|A|', 'DalCorso|Giovanni|G|', 'Guzzo|Flavia|F|', 'Furini|Antonella|A|']
D017360:Arabidopsis D029681:Arabidopsis Proteins D015415:Biomarkers D002736:Chloroplasts D002853:Chromatography, Liquid D016002:Discriminant Analysis D018506:Gene Expression Regulation, Plant D007425:Intracellular Membranes D016018:Least-Squares Analysis D050356:Lipid Metabolism D013058:Mass Spectrometry D055442:Metabolome D055432:Metabolomics D009154:Mutation D018515:Plant Leaves D025341:Principal Component Analysis D011494:Protein Kinases D060888:Real-Time Polymerase Chain Reaction D059467:Transcriptome
ABC1K7 ABC1K8 Lipidomics ABC1K proteins Galactolipids Oxylipins