Proceedings of the National Academy of Sciences · 2010 · 147 citations · 31 references
Life SciencesPlant BiologyPlant SciencesLipid BiochemistryMetabolismPlant BiochemistryFatty Acid MetabolismLipid ChemistryLipid DisordersLipid HomeostasisLipid MetabolismLipid StorageFatty AcidsIntracellular Lipid AccumulationLipid AccumulationLoss-of-function MutationsNeutral Lipid AccumulationNeutral Lipid Storage DiseasePlant Lipid MetabolismTriacylglycerol Accumulation
CGI-58 is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologous CGI-58 gene in Arabidopsis thaliana resulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets from cgi-58 loss-of-function mutants showed they contain triacylglycerols with common leaf-specific fatty acids. Leaves of mature cgi-58 plants exhibited a marked increase in absolute triacylglycerol levels, more than 10-fold higher than in wild-type plants. Lipid levels in the oil-storing seeds of cgi-58 loss-of-function plants were unchanged, and unlike mutations in β-oxidation, the cgi-58 seeds germinated and grew normally, requiring no rescue with sucrose. We conclude that the participation of CGI-58 in neutral lipid homeostasis of nonfat-storing tissues is similar, although not identical, between plant and animal species. This unique insight may have implications for designing a new generation of technologies that enhance the neutral lipid content and composition of crop plants.
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