Regulation of PPi Levels Through the Vacuolar Membrane H+-Pyrophosphatase

Excess Pyrophosphate Restrains Pavement Cell Morphogenesis and Alters Organ Flatness in Arabidopsis thaliana

“…Simultaneously, in nearly 200 different metabolic reactions (Heinonen, 2001)including DNA replication, amino acid activation, and protein and cell wall biosynthesis-they produce pyrophosphate (PPi). PPi is a toxic molecule that if not immediately hydrolyzed by solubletype pyrophosphatases (sPPases) and/or membrane-bound pyrophosphatases (H + -PPases) (Ferjani et al, 2014;Segami et al, 2018), irreversibly arrests the above metabolic reaction.…”

Vacuolar H+-Pyrophosphatase and Cytosolic Soluble Pyrophosphatases Cooperatively Regulate Pyrophosphate Levels in Arabidopsis thaliana

“…Inorganic pyrophosphate (PPi) is a high-energy phosphate compound that is generated as a by-product of over 200 metabolic reactions, including fatty acid b-oxidation and DNA, RNA, aminoacyl-tRNA, and polysaccharide biosynthesis (Heinonen, 2001;Ferjani et al, 2014). In most organisms other than plants, PPi hydrolysis is catalyzed by the soluble form of inorganic pyrophosphatase (sPPase; EC 3.6.1.1).…”

Roles of the vacuolar H⁺-PPase in seed storage oil mobilization and plant development

“…Given the Suc-related phenotype of the fugu5 mutant, we discuss reactions that are closely related to carbohydrate metabolism. Other reactions that produce PPi have been recently summarized in detail (Ferjani et al 2014, Heinonen 2001.…”

“…It is generally believed that sPPase activities are negligible in the plant cytosol (Weiner et al 1987). However, the Arabidopsis genome possesses six sPPase genes: AtPPa1 through AtPPa6, which correspond to At1g01050, At2g18230, At2g46860, At3g53620, At4g01480, and At5g09650, respectively (Meyer et al 2012, Ferjani et al 2014. These homologs are subdivided into prokaryotic (AtPPa1 to AtPPa5) and eukaryotic types (AtPPa6) (Rojas-Beltrán et al 1999, Gómez-García et al 2006.…”

“…Such compensatory coordination between cell cycling and expansion is known to occur in the leaves of many mutants and transgenic lines, and has been the topic of several investigations. For example, by considering the manner through which a cell reaches its ultimate size and performing kinematic analyses of cell size dynamism, three classes of compensation have been identified: Class I, an enhanced postmitotic cell expansion rate (seen in angustifolia [an]3-4, fugu2-1/fasciata [fas]1-5, and erecta [er]-102); Class II, an extended post-mitotic cell expansion period (seen in fugu5-1); and Class III, increase in the size of dividing cells (seen in KIP-RELATED PROTEIN 2 [KRP2] over-expressing cells) (Ferjani et al 2007(Ferjani et al , 2008(Ferjani et al , 2010(Ferjani et al , 2013a(Ferjani et al , 2013b(Ferjani et al , 2014. Furthermore, during compensation, cell-autonomous and non-cell-autonomous pathways have been identified (Kawade et al 2010, 2013, Ferjani et al 2013a.…”