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The evolutionarily conserved target of rapamycin complex 1 (TORC1) controls growth-related processes such as protein, nucleotide, and lipid metabolism in response to growth hormones, energy/ATP levels, and amino acids. Its deregulation is associated with cancer, type 2 diabetes, and obesity. Among other substrates, mammalian TORC1 directly phosphorylates and inhibits the phosphatidate phosphatase lipin-1, a central enzyme in lipid metabolism that provides diacylglycerol for the synthesis of membrane phospholipids and/or triacylglycerol as neutral lipid reserve. Here, we show that yeast TORC1 inhibits the function of the respective lipin, Pah1, to prevent the accumulation of triacylglycerol. Surprisingly, TORC1 regulates Pah1 in part indirectly by controlling the phosphorylation status of Nem1 within the Pah1-activating, heterodimeric Nem1-Spo7 protein phosphatase module. Our results delineate a hitherto unknown TORC1 effector branch that controls lipin function in yeast, which, given the recent discovery of Nem1-Spo7 orthologous proteins in humans, may be conserved. [ABSTRACT FROM AUTHOR]

Abstract: Under phosphate deprivation, higher plants change their lipid composition and recycle phosphate from phospholipids. A phospholipase D, PLDζ2, is involved in this recycling and in other cellular functions related to plant development. We investigated the localization of Arabidopsis PLDζ2 by cell fractionation and in vivo GFP confocal imaging. AtPLDζ2 localizes to the tonoplast and the Nter regulatory domain is sufficient for its sorting. Under phosphate deprivation, AtPLDζ2 remains located in the tonoplast but its distribution is uneven. We observed PLDζ2-enriched tonoplast domains preferentially positioned close to mitochondria and beside chloroplasts. In absence of PLDζ2, membrane developments were visualized inside vacuoles. [Copyright &y& Elsevier]