Polyphosphate‐hydrolysis ‐ a protective mechanism against alkaline stress?

Pick, Uri; Bental, Michal; Chitlaru, Edith; Weiss, Martin

doi:10.1016/0014-5793(90)81318-i

Cited by 74 publications

(11 citation statements)

References 13 publications

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“…PolyP has also been suggested to function in the neutralization of microalgal cells that become alkalinized when incubated in high concentrations of ammonium (Pick et al, 1990). In Dunaliella salina, the addition of 20 mM ammonium increased the cytosolic pH and reduced cellular ATP levels.…”

Section: Polyp During Stationary Phase and Other Abiotic Stressesmentioning

confidence: 99%

Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae

2020

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Polyphosphate (polyP), a polymer of orthophosphate (PO 4 3-) of varying lengths, has been identified in all kingdoms of life. It can serve as a source of chemical bond energy (phosphoanhydride bond) that may have been used by biological systems prior to the evolution of ATP. Intracellular polyP is mainly stored as granules in specific vacuoles called acidocalcisomes, and its synthesis and accumulation appear to impact a myriad of cellular functions. It serves as a reservoir for inorganic PO 4 3and an energy source for fueling cellular metabolism, participates in maintaining adenylate and metal cation homeostasis, functions as a scaffold for sequestering cations, exhibits chaperone function, covalently binds to proteins to modify their activity, and enables normal acclimation of cells to stress conditions. PolyP also appears to have a role in symbiotic and parasitic associations, and in higher eukaryotes, low polyP levels seem to impact cancerous proliferation, apoptosis, procoagulant and proinflammatory responses and cause defects in TOR signaling. In this review, we discuss the metabolism, storage, and function of polyP in photosynthetic microbes, which mostly includes research on green algae and cyanobacteria. We focus on factors that impact polyP synthesis, specific enzymes required for its synthesis and degradation, sequestration of polyP in acidocalcisomes, its role in cellular energetics, acclimation processes, and metal homeostasis, and then transition to its potential applications for bioremediation and medical purposes.

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Section: Polyp During Stationary Phase and Other Abiotic Stressesmentioning

confidence: 99%

Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae

2020

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“…Remarkably, human mitochondrial NAD kinase has been recently identified to have the ability to utilize both ATP and polyP as the phosphoryl donor (Ohashi et al, 2012). Neglected and long regarded a molecular fossil, polyP has a variety of significant functions in bacteria such as a (i) source of energy (Kulaev, 1979; Wood and Clark, 1988; Kulaev et al, 1999b), (ii) phosphate reservoir (Kulaev et al, 1999b), (iii) donor for sugar and adenylate kinases (Bonting et al, 1991; Hsieh et al, 1993; Phillips et al, 1993), (iv) chelator for divalent cations (Van Veen et al, 1993), (v) buffer against alkaline stress (Pick et al, 1990), (vi) regulator of development (Gezelius et al, 1973), and (vii) structural element in competence for DNA entry and transformation (Reusch and Sadoff, 1988). Even though most of polyP research has been performed in microorganisms, the presence of polyP has been demonstrated in many mammalian tissues (Figure 4) such as rodent liver, kidney, lungs, brain, and heart (Kumble and Kornberg, 1995), rabbit heart (Seidlmayer et al, 2012a,b), as well as in human granulocytes (Cowling and Birnboim, 1994), platelets (Smith et al, 2006; Smith and Morrissey, 2008a; Morrissey et al, 2012), and fibroblasts (Pisoni and Lindley, 1992).…”

Section: What Is Inorganic Polyphosphate?mentioning

confidence: 99%

Role of Î²-hydroxybutyrate, its polymer poly-Î²-hydroxybutyrate and inorganic polyphosphate in mammalian health and disease

2014

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We provide a comprehensive review of the role of β-hydroxybutyrate (β-OHB), its linear polymer poly-β-hydroxybutyrate (PHB), and inorganic polyphosphate (polyP) in mammalian health and disease. β-OHB is a metabolic intermediate that constitutes 70% of ketone bodies produced during ketosis. Although ketosis has been generally considered as an unfavorable pathological state (e.g., diabetic ketoacidosis in type-1 diabetes mellitus), it has been suggested that induction of mild hyperketonemia may have certain therapeutic benefits. β-OHB is synthesized in the liver from acetyl-CoA by β-OHB dehydrogenase and can be used as alternative energy source. Elevated levels of PHB are associated with pathological states. In humans, short-chain, complexed PHB (cPHB) is found in a wide variety of tissues and in atherosclerotic plaques. Plasma cPHB concentrations correlate strongly with atherogenic lipid profiles, and PHB tissue levels are elevated in type-1 diabetic animals. However, little is known about mechanisms of PHB action especially in the heart. In contrast to β-OHB, PHB is a water-insoluble, amphiphilic polymer that has high intrinsic viscosity and salt-solvating properties. cPHB can form non-specific ion channels in planar lipid bilayers and liposomes. PHB can form complexes with polyP and Ca2+ which increases membrane permeability. The biological roles played by polyP, a ubiquitous phosphate polymer with ATP-like bonds, have been most extensively studied in prokaryotes, however polyP has recently been linked to a variety of functions in mammalian cells, including blood coagulation, regulation of enzyme activity in cancer cells, cell proliferation, apoptosis and mitochondrial ion transport and energy metabolism. Recent evidence suggests that polyP is a potent activator of the mitochondrial permeability transition pore in cardiomyocytes and may represent a hitherto unrecognized key structural and functional component of the mitochondrial membrane system.

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“…N is the limiting factor in P accumulation because N is required in protein synthesis, such as of ribosomal RNA, which incorporates P [ 33 , 42 ]. In the case of N limitation, uptake can still occur through a luxury uptake pathway where polyphosphates accumulate within C. vulgaris cells, which hydrolyse these to PO 4 -P [ 67 ]. This described effect of N limitation on P removal was observed in a study conducted by Li et al [ 26 ] using a mixture of Chlorella sp.…”

Section: Discussionmentioning

confidence: 99%

Comparing Nutrient Removal from Membrane Filtered and Unfiltered Domestic Wastewater Using Chlorella vulgaris

Mayhead

Silkina

Llewellyn

et al. 2018

Biology

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The nutrient removal efficiency of Chlorella vulgaris cultivated in domestic wastewater was investigated, along with the potential to use membrane filtration as a pre-treatment tool during the wastewater treatment process. Chlorella vulgaris was batch cultivated for 12 days in a bubble column system with two different wastewater treatments. Maximum uptake of 94.18% ammonium (NH4-N) and 97.69% ortho-phosphate (PO4-P) occurred in 0.2 μm membrane filtered primary wastewater. Membrane filtration enhanced the nutrient uptake performance of C. vulgaris by removing bacteria, protozoa, colloidal particles and suspended solids, thereby improving light availability for photosynthesis. The results of this study suggest that growing C. vulgaris in nutrient rich membrane filtered wastewater provides an option for domestic wastewater treatment to improve the quality of the final effluent.

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Polyphosphate‐hydrolysis ‐ a protective mechanism against alkaline stress?

Cited by 74 publications

References 13 publications

Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae

Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae

Role of Î²-hydroxybutyrate, its polymer poly-Î²-hydroxybutyrate and inorganic polyphosphate in mammalian health and disease

Comparing Nutrient Removal from Membrane Filtered and Unfiltered Domestic Wastewater Using Chlorella vulgaris

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