Abstract
It is believed that phosphatidylinositol (PI) metabolism plays a central role in signalling pathways in both animals and higher plants. PI is synthesized from CDP-diacylglycerol (CDP-DG) and myo-inositol by phosphatidylinositol synthase (PI synthase, EC 2.7.8.11). Here we report the identification of a plant cDNA (AtPIS1) encoding a 26 kDa PI synthase from Arabidopsis thaliana. The plant enzyme as deduced from its cDNA sequence shares 35-41% identical amino acids with PI synthases from Saccharomyces cerevisiae and mammals. AtPIS1 functionally complements a mutant of S. cerevisiae with a lesion in PI synthase, and recombinant AtPIS1 protein present in yeast membranes strongly depends on the two principal substrates, myo-inositol and CDP-DG, and requires Mg2+ ions for full activity.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Arabidopsis / enzymology
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Arabidopsis / genetics*
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Arabidopsis Proteins
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Blotting, Northern
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CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase
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Cloning, Molecular
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DNA, Complementary / chemistry
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DNA, Complementary / genetics
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Gene Expression Regulation, Enzymologic
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Gene Expression Regulation, Plant
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Genetic Complementation Test
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Membrane Proteins
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Molecular Sequence Data
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Mutation
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RNA, Plant / genetics
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RNA, Plant / metabolism
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Saccharomyces cerevisiae / enzymology
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Saccharomyces cerevisiae / genetics*
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Sequence Alignment
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Sequence Analysis, DNA
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Sequence Homology, Amino Acid
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Tissue Distribution
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Transferases (Other Substituted Phosphate Groups) / genetics*
Substances
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Arabidopsis Proteins
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DNA, Complementary
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Membrane Proteins
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RNA, Plant
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Transferases (Other Substituted Phosphate Groups)
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ATPIS1 protein, Arabidopsis
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CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase