Identification of AtPIS, a phosphatidylinositol synthase from Arabidopsis.

摘要: Phosphatidylinositol synthase is the enzyme responsible for synthesis of phosphatidylinositol, a key phospholipid component all eukaryotic membranes and precursor messenger molecules involved in signal transduction pathways calcium-dependent responses cell. Using amino acid sequence yeast as probe, we identified an Arabidopsis expressed tag potentially encoding plant enzyme. Sequencing entire cDNA confirmed homology between two proteins. Functional assays, performed by overexpression Escherichia coli, bacteria which lacks phosphatidylinositol activity, showed that protein induced accumulation bacterial cells. Analysis enzymatic activity vitro occurs when CDP-diacylglycerol myo-inositol only are provided substrates, it requires manganese or magnesium ions at least part located to membrane fraction. These data allowed us conclude codes synthase. A single AtPIS genetic locus was found, mapped chromosome 1.