Assessment of mitochondria as a compartment for phosphatidylinositol synthesis in Solanum tuberosum

作者：de Virville Jacques Davy; Brown Spencer; Cochet Francoise; Soler Marie Noelle; Hoffelt Michele; Ruelland Eric; Zachowski Alain; Collin Sylvie^*

来源：Plant Physiology and Biochemistry, 2010, 48(12): 952-960.

DOI：10.1016/j.plaphy.2010.09.004

• Phosphatidylinositol synthase
• Phospholipid synthesis
• Mitochondria
• Outer mitochondrial membrane
• Solanum tuberosum
• Sub-cellular localization
• GFP

The outer mitochondrial membrane is particularly rich in phosphatidylinositol (Ptdlns), a phospholipid found in different amounts in all eukaryotic membranes, but not synthesized in situ by all. PtdIns is therefore subjected to traffic from the synthesizing membranes to the non-synthesizing ones. The contribution of mitochondria to the cell Ptdlns pool has never been the focus of a specific study in plants, whereas in yeast, the presence of the enzyme responsible for synthesis, PtdIns synthase (PIS, cytidine 5'-diphospho-1,2-diacyl-sn-glycerol:myo-inositol-phosphatidyltransferase, EC 2.7.8.11), has clearly been demonstrated in mitochondria. As these organelles have now been shown to be responsible for the synthesis of several lipids, the present work aimed at evaluating mitochondria as a compartment for the synthesis of Ptdlns in plants. The sub-cellular localization of PIS was studied in Solanum tuberosum L by membrane fractionation, enzymatic analysis and by confocal microscopy in living cells. In potato, beside the endoplasmic reticulum, the activity of PIS was found to be tightly associated to mitochondria. Using a fluorescent reporter fusion, the enzyme was also found to be associated to these organelles. The enzyme was not present at the plasma membrane. A comparison of the localization in other cell systems suggests that the mitochondrial localization could be regulated.

• 出版日期2010-12