Phosphoenolpyruvate Carboxylase from C4 Leaves Is Selectively Targeted for Inhibition by Anionic Phospholipids
Phosphoenolpyruvate Carboxylase from C4 Leaves Is Selectively Targeted for Inhibition by Anionic Phospholipids
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DOI：
10.1104/pp.109.150326
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发表时间：
2010-02-01
期刊：
影响因子：
7.4
通讯作者：
Testerink, Christa
中科院分区：
文献类型：
--
作者：
Monreal, Jose A.;McLoughlin, Fionn;Testerink, Christa
Phosphoenolpyruvate carboxylase (PEPC; EC 4.1. 1.31) is an enzyme playing a crucial role in photosynthesis of C4 plants. Here, we identify anionic phospholipids as novel regulators that inhibit C4 PEPC activity and provide evidence that the enzyme partially localizes to membranes. PEPC catalyzes the b-carboxylation of phosphoenolpyruvate (PEP) in a reaction that yields oxaloacetate and inorganic phosphate. In C4 plants, it notably performs the initial fixation of atmospheric CO2 in photosynthesis, while it also has an anaplerotic function in coordinating carbon and nitrogen metabolism in all plants (Chollet et al., 1996; Vidal and Chollet, 1997). The PEPC protein is subject to distinct but interrelated mechanisms of posttranslational regulation by allosteric positive (eg Glc-6-P, triose-P) or negative (eg L-malate, Asp) effectors, as well as phosphorylation of the protein at its N-terminal domain (Nimmo, 2003).Previously, we have identified C3 PEPC isoforms as phosphatidic acid (PA)-binding proteins from tomato (Solanum lycopersicum) and Arabidopsis (Arabidopsis thaliana) suspension-cultured cells in a proteomics screen (Testerink et al., 2004). Phospholipids can affect both localization and activity of a diverse range of proteins, including protein kinases and phosphatases (Testerink and Munnik, 2005; Hurley, 2006; Lemmon, 2008; Munnik and Testerink, 2009; Stahelin, 2009), but also directly regulate metabolic enzymes, such as Escherichia coli pyruvate oxidase (Neumann et al., 2008), mammalian CTP: phosphocholine cytidyltransferase (Johnson et al., 2003; Cornell and Taneva, 2006; Taneva
