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Biosynthesis and possible functions of inositol pyrophosphates in plants.

Williams SP, Gillaspy GE, Perera IY - Front Plant Sci (2015)

Bottom Line: Most eukaryotes synthesize the precursor molecule, myo-inositol (1,2,3,4,5,6)-hexakisphosphate (InsP6), which can serve as a signaling molecule or as storage compound of inositol, phosphorus, and minerals (referred to as phytic acid).Recent work has delineated that Arabidopsis has two genes capable of PP-InsP5 synthesis, and PPx-InsPs have been detected across the plant kingdom.This review will detail the known roles of PPx-InsPs in yeast and animal systems, and provide a description of recent data on the synthesis and accumulation of these novel molecules in plants, and potential roles in signaling.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry, Virginia Polytechnic and State University Blacksburg, VA, USA.

ABSTRACT
Inositol phosphates (InsPs) are intricately tied to lipid signaling, as at least one portion of the inositol phosphate signaling pool is derived from hydrolysis of the lipid precursor, phosphatidyl inositol (4,5) bisphosphate. The focus of this review is on the inositol pyrophosphates, which are a novel group of InsP signaling molecules containing diphosphate or triphosphate chains (i.e., PPx) attached to the inositol ring. These PPx-InsPs are emerging as critical players in the integration of cellular metabolism and stress signaling in non-plant eukaryotes. Most eukaryotes synthesize the precursor molecule, myo-inositol (1,2,3,4,5,6)-hexakisphosphate (InsP6), which can serve as a signaling molecule or as storage compound of inositol, phosphorus, and minerals (referred to as phytic acid). Even though plants produce huge amounts of precursor InsP6 in seeds, almost no attention has been paid to whether PPx-InsPs exist in plants, and if so, what roles these molecules play. Recent work has delineated that Arabidopsis has two genes capable of PP-InsP5 synthesis, and PPx-InsPs have been detected across the plant kingdom. This review will detail the known roles of PPx-InsPs in yeast and animal systems, and provide a description of recent data on the synthesis and accumulation of these novel molecules in plants, and potential roles in signaling.

No MeSH data available.


Synthesis of inositol pyrophosphate. Overview of the Inositol phosphate pathway, including both lipid dependent and lipid independent routes for synthesis of InsP6. Inositol Pyrophosphate (PPx-InsP) synthesis is indicated in red. Major lipid and inositol species are indicated in black and key enzymes are indicated in brown. A more detailed outline of PPx-InsP synthesis is depicted in Figure 2. The blue and orange asterisks correspond to the colored boxes in Figure 2.
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Figure 1: Synthesis of inositol pyrophosphate. Overview of the Inositol phosphate pathway, including both lipid dependent and lipid independent routes for synthesis of InsP6. Inositol Pyrophosphate (PPx-InsP) synthesis is indicated in red. Major lipid and inositol species are indicated in black and key enzymes are indicated in brown. A more detailed outline of PPx-InsP synthesis is depicted in Figure 2. The blue and orange asterisks correspond to the colored boxes in Figure 2.

Mentions: Myo-inositol (inositol) signaling is much like a language in that each molecular species used in the pathway, whether lipid or soluble in nature, can convey specific information to the cell, like a word. In this analogy, each combination of different numbers and positions of phosphates on the inositol ring and the presence of diacylglycerol linked via the C1 of inositol, also convey unique information (see Figure 1). Comprehensive analyses of both inositol and inositol phospholipids in signaling have been previously reviewed (Van Leeuwen et al., 2004; Gillaspy, 2011; Heilmann and Heilmann, 2014), so this review focuses on new inositol signaling molecules, the di-phospho (PP) and tri-phospho (PPP) inositol phosphates (PPx-InsPs), also known as inositol pyrophosphates. These high-energy molecules have been studied in non-plant eukaryotes, however, their existence and role in plants is newly emerging. The main questions regarding PPx-InsPs are: can these molecules be detected in plants, how are they synthesized and what type of information do they convey? Recent work addressing these questions will be discussed in the broader context of understanding how PPx-InsPs function in eukaryotes.


Biosynthesis and possible functions of inositol pyrophosphates in plants.

Williams SP, Gillaspy GE, Perera IY - Front Plant Sci (2015)

Synthesis of inositol pyrophosphate. Overview of the Inositol phosphate pathway, including both lipid dependent and lipid independent routes for synthesis of InsP6. Inositol Pyrophosphate (PPx-InsP) synthesis is indicated in red. Major lipid and inositol species are indicated in black and key enzymes are indicated in brown. A more detailed outline of PPx-InsP synthesis is depicted in Figure 2. The blue and orange asterisks correspond to the colored boxes in Figure 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4325660&req=5

Figure 1: Synthesis of inositol pyrophosphate. Overview of the Inositol phosphate pathway, including both lipid dependent and lipid independent routes for synthesis of InsP6. Inositol Pyrophosphate (PPx-InsP) synthesis is indicated in red. Major lipid and inositol species are indicated in black and key enzymes are indicated in brown. A more detailed outline of PPx-InsP synthesis is depicted in Figure 2. The blue and orange asterisks correspond to the colored boxes in Figure 2.
Mentions: Myo-inositol (inositol) signaling is much like a language in that each molecular species used in the pathway, whether lipid or soluble in nature, can convey specific information to the cell, like a word. In this analogy, each combination of different numbers and positions of phosphates on the inositol ring and the presence of diacylglycerol linked via the C1 of inositol, also convey unique information (see Figure 1). Comprehensive analyses of both inositol and inositol phospholipids in signaling have been previously reviewed (Van Leeuwen et al., 2004; Gillaspy, 2011; Heilmann and Heilmann, 2014), so this review focuses on new inositol signaling molecules, the di-phospho (PP) and tri-phospho (PPP) inositol phosphates (PPx-InsPs), also known as inositol pyrophosphates. These high-energy molecules have been studied in non-plant eukaryotes, however, their existence and role in plants is newly emerging. The main questions regarding PPx-InsPs are: can these molecules be detected in plants, how are they synthesized and what type of information do they convey? Recent work addressing these questions will be discussed in the broader context of understanding how PPx-InsPs function in eukaryotes.

Bottom Line: Most eukaryotes synthesize the precursor molecule, myo-inositol (1,2,3,4,5,6)-hexakisphosphate (InsP6), which can serve as a signaling molecule or as storage compound of inositol, phosphorus, and minerals (referred to as phytic acid).Recent work has delineated that Arabidopsis has two genes capable of PP-InsP5 synthesis, and PPx-InsPs have been detected across the plant kingdom.This review will detail the known roles of PPx-InsPs in yeast and animal systems, and provide a description of recent data on the synthesis and accumulation of these novel molecules in plants, and potential roles in signaling.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry, Virginia Polytechnic and State University Blacksburg, VA, USA.

ABSTRACT
Inositol phosphates (InsPs) are intricately tied to lipid signaling, as at least one portion of the inositol phosphate signaling pool is derived from hydrolysis of the lipid precursor, phosphatidyl inositol (4,5) bisphosphate. The focus of this review is on the inositol pyrophosphates, which are a novel group of InsP signaling molecules containing diphosphate or triphosphate chains (i.e., PPx) attached to the inositol ring. These PPx-InsPs are emerging as critical players in the integration of cellular metabolism and stress signaling in non-plant eukaryotes. Most eukaryotes synthesize the precursor molecule, myo-inositol (1,2,3,4,5,6)-hexakisphosphate (InsP6), which can serve as a signaling molecule or as storage compound of inositol, phosphorus, and minerals (referred to as phytic acid). Even though plants produce huge amounts of precursor InsP6 in seeds, almost no attention has been paid to whether PPx-InsPs exist in plants, and if so, what roles these molecules play. Recent work has delineated that Arabidopsis has two genes capable of PP-InsP5 synthesis, and PPx-InsPs have been detected across the plant kingdom. This review will detail the known roles of PPx-InsPs in yeast and animal systems, and provide a description of recent data on the synthesis and accumulation of these novel molecules in plants, and potential roles in signaling.

No MeSH data available.