Subcellular localization and enzymatic properties of rat liver phosphatidylinositol-4-phosphate kinase

Lundberg, Gunilla A.; Jergil, Bengt; Sundler, Roger

doi:10.1016/0167-4889(85)90009-6

Cited by 49 publications

(12 citation statements)

References 42 publications

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“…The relative contribution of the PE biosynthetic pathways to cellular PE content has not been firmly established, but it appears to depend on the cell type. In rat liver/hepatocytes and hamster heart, the CDP-ethanolamine pathway has been reported to produce the majority of PE (109)(110)(111)(112). In contrast, in many types of cultured cells, .80% of PE is apparently made from the decarboxylation of PS via PSD, even when ethanolamine is provided in the culture medium as a substrate for the CDP-ethanolamine pathway (74,113,114).…”

Section: Pe Synthesismentioning

confidence: 99%

Thematic Review Series: Glycerolipids. Phosphatidylserine and phosphatidylethanolamine in mammalian cells: two metabolically related aminophospholipids

Vance

2008

Journal of Lipid Research

420

355

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Phosphatidylserine(PS)andphosphatidylethanolamine (PE) are two aminophospholipids whose metabolism is interrelated. Both phospholipids are components of mammalian cell membranes and play important roles in biological processes such as apoptosis and cell signaling. PS is synthesized in mammalian cells by base-exchange reactions in which polar head groups of preexisting phospholipids are replaced by serine. PS synthase activity resides primarily on mitochondria-associated membranes and is encoded by two distinct genes. Studies in mice in which each gene has been individually disrupted are beginning to elucidate the importance of these two synthases for biological functions in intact animals. PE is made in mammalian cells by two completely independent major pathways. In one pathway, PS is converted into PE by the mitochondrial enzyme PS decarboxylase. In addition, PE is made via the CDP-ethanolamine pathway, in which the final reaction occurs on the endoplasmic reticulum and nuclear envelope. The relative importance of these two pathways of PE synthesis has been investigated in knockout mice. Elimination of either pathway is embryonically lethal, despite the normal activity of the other pathway. PE can also be generated from a base-exchange reaction and by the acylation of lyso-PE. Cellular levels of PS and PE are tightly regulated by the implementation of multiple compensatory mechanisms.-Vance, J. E. Phosphatidylserine and phosphatidylethanolamine in mammalian cells: two metabolically related aminophospholipids.

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Section: Pe Synthesismentioning

confidence: 99%

Thematic Review Series: Glycerolipids. Phosphatidylserine and phosphatidylethanolamine in mammalian cells: two metabolically related aminophospholipids

Vance

2008

Journal of Lipid Research

420

355

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“…3H-Labeled phosphoinositides remaining after incubation were also checked by TLC on silica gel H (Merck) impregnated with potassium oxalate (10,14).…”

Section: Phospholipase C Assaymentioning

confidence: 99%

Polyphosphoinositide Phospholipase C in Plasma Membranes of Wheat (Triticum aestivum L.)

Pical

Sandelius²,

Melin³

et al. 1992

Plant Physiol.

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Polyphosphoinositide-specific phospholipase C activity was present in plasma membranes isolated from different tissues of several higher plants. Phospholipase C activities against added phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bisphosphate (PIP2) were further characterized in plasma membrane fractions isolated from shoots and roots of dark-grown wheat (Triticum aestivum L. cv Drabant) seedlings. In right-side-out (70-80% apoplastic side out) plasma membrane vesicles, the activities were increased 3 to 5 times upon addition of 0.01 to 0.025% (w/ v) sodium deoxycholate, whereas in fractions enriched in insideout (70-80% cytoplasmic side out) vesicles, the activities were only slightly increased by detergent. Furthermore, the activities of inside-out vesicles in the absence of detergent were very close to those of right-side-out vesicles in the presence of optimal detergent concentration. This verifies the general assumption that polyphosphoinositide phospholipase C activity is located at the cytoplasmic surface of the plasma membrane. PIP and PIP2 phospholipase C was dependent on Ca21 with maximum activity at 10 to 100 Mm free Ca2 and half-maximal activation at 0.1 to 1 Mm free Ca2. In the presence of 10 gM Ca21, 1 to 2 mM MgCI2 or MgSO4 further stimulated the enzyme activity. The other divalent chloride salts tested (1.5 mm Ba2", Co2+, Cu2+, Mn2+, Ni2+, and Zn2+) inhibited the enzyme activity. The stimulatory effect by Mg2+ was observed also when 35 mm NaCI was included. Thus, the PIP and PIP2 phospholipase C exhibited maximum in vitro activity at physiologically relevant ion concentrations. The plant plasma membrane also possessed a phospholipase C activity against phosphatidylinositol that was 40 times lower than that observed with PIP or PIP2 as substrate. The phosphatidylinositol phospholipase C activity was dependent on Ca2 , with maximum activity at 1 mm CaC12, and could not be further stimulated by Mg2+.animal cells, phospholipase C-catalyzed production of the second messengers inositol 1,4,5-trisphosphate and diacylglycerol from PIP22 is a key event in the transduction of agonist-dependent signals over the plasma membrane (1,3,15). PIP2 is formed by a two-step phosphorylation of PI by PI kinase and PIP kinase, enzymes that are also present in plant plasma membranes (18,24,29). Because phospholipase C, preferentially active on PIP and PIP2, has also been identified in plasma membranes from plants (7,17,30), there is an enzymic basis for signal transduction through hydrolysis of polyphosphoinositides. However, very little is known about the mechanism operating in the plant plasma membrane, in part due to the scant knowledge about phospholipase C.In this communication, we present evidence for the localization of polyphosphoinositide phospholipase C activity in wheat (Triticum aestivum L. cv Drabant) plasma membranes to the cytoplasmic surface of the membrane. We also present a further characterization of the in vitro properties of the enzyme activity. MATERIALS AND METHODS

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“…Apart from these more general interactions, A TP at physiological concentrations can control a num ber of cellular variables such as a voltage-independent K+ conductivity in cardiac muscle (48) and pancreatic B cells (15). Furthermore, a reduced availability of ATP to the enzyme phosphatidylinositol-4-phosphate kinase (43) appears to lead to a decrease in the contractility of smooth muscle under hypoxic conditions (14).…”

Section: Erythropoietin Production and The Oxygen Sensor Are Located mentioning

confidence: 99%

Oxygen Sensing in the Kidney and its Relation to Erythropoietin Production

Bauer

Kurtz²

1989

Annu. Rev. Physiol.

101

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Subcellular localization and enzymatic properties of rat liver phosphatidylinositol-4-phosphate kinase

Cited by 49 publications

References 42 publications

Thematic Review Series: Glycerolipids. Phosphatidylserine and phosphatidylethanolamine in mammalian cells: two metabolically related aminophospholipids

Thematic Review Series: Glycerolipids. Phosphatidylserine and phosphatidylethanolamine in mammalian cells: two metabolically related aminophospholipids

Polyphosphoinositide Phospholipase C in Plasma Membranes of Wheat (Triticum aestivum L.)

Oxygen Sensing in the Kidney and its Relation to Erythropoietin Production

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