Phosphorylation of signaling phospholipids in Coffea arabica cells

Palma, Graciela Racagni-Di; Brito‐Argáez, Ligia; Hernández‐Sotomayor, S.M. Teresa

doi:10.1016/s0981-9428(02)01450-x

Cited by 15 publications

(10 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phosphorylation of endogenous PtdIns was linear for 5 min with 60 μg protein for stimulated and non‐stimulated aleurones. Reaction was stopped by addition of 1.5 ml CHCl 3 /CH 3 OH (1:2, v/v) (Racagni‐Di Palma et al 2002). PI3 kinase assay was performed using Saccharomyces cerevisiae membrane fraction (approximately 4 μg protein) as control and sonicated PtdIns as substrate (0.2 mg ml −1 ).…”

Section: Methodsmentioning

confidence: 99%

Phosphatidylinositol kinases as regulators of GA‐stimulated α‐amylase secretion in barley (Hordeum vulgare)

Villasuso

Racagni

Machado

2008

Physiologia Plantarum

View full text Add to dashboard Cite

Phosphorylated derivatives of phosphatidylinositol, in association with phosphatidylinositol 3-kinase (PI3 kinase, EC 2.7.1.137) and phosphatidylinositol 4-kinase (PI4 kinase, EC 2.7.1.67), play a key role in regulation of fundamental cell processes. We present evidence for a relationship between alpha-amylase (EC 3.2.1.1) secretion regulated by GA and levels of phosphatidylinositol 3-phosphate and phosphatidylinositol 4-phosphate (PtdIns(4)P) in barley (Hordeum vulgare). Microsomal membranes were incubated in the presence of [gamma-(32)P]ATP, and radiolabeled membrane lipids were extracted and separated by TLC using a boric acid system. Treatment of aleurone layers with GA for short or long periods of time increased PI4 kinase activity. To evaluate the effect of PtdIns(4)P levels on GA signaling, we used phenylarsine oxide (PAO), an inhibitor of PI4 kinase activity. PAO reversibly reduced the alpha-amylase secretion and protoplast cell vacuolation in a dose-dependent manner. Wortmannin showed a similar inhibitory effect on alpha-amylase secretion and PI4 kinase activity. GA evoked only a long-term increase in PI3 kinase activity, which was also affected by PAO. The effect of PAO was suppressed by the reducing agent 2,3-dimercapto-1-propanol (BAL), leading to restoration of secretion, vacuolation and PI4 kinase activity. In contrast, the effect of PAO on PI3 kinase activity was not abolished by BAL, suggesting that PI3 kinase is not involved in the secretion process. Likewise, the compound LY294002 inhibited PI3 kinase but had no effect on the secretion process. These findings indicate that PI4 kinase acts as a positive regulator of early GA signaling in aleurone.

show abstract

Section: Methodsmentioning

confidence: 99%

Phosphatidylinositol kinases as regulators of GA‐stimulated α‐amylase secretion in barley (Hordeum vulgare)

Villasuso

Racagni

Machado

2008

Physiologia Plantarum

View full text Add to dashboard Cite

show abstract

“…The reaction was stopped after 2 min by adding 1.5 ml of chloroform/methanol (1/2, v/v), followed by 0.5 ml of 2.4 N HCl and 0.5 ml of chloroform. Phosphorylated lipids were extracted from the membranes (22) and then separated by TLC (23). The position of each radiolabeled phosphorylated lipid was determined by autoradiography on Kodak film.…”

Section: Methodsmentioning

confidence: 99%

Lipid Profiling by Electrospray Ionization Tandem Mass Spectrometry and the Identification of Lipid Phosphorylation by Kinases in Potato Stolons

Cenzano

Cantoro

Hernández‐Sotomayor

et al. 2011

J. Agric. Food Chem.

View full text Add to dashboard Cite

There is limited information about the involvement of lipids and esterified fatty acids in signaling pathways during plant development. The purpose of this study was to evaluate the lipid composition and molecular species of potato (Solanum tuberosum L., cv. Spunta) stolons and to identify phosphorylated lipids in the first two developmental stages of tuber formation. Lipid profiling was determined using ESI-MS/MS, a useful method for the determination of the biosynthesis and catabolism of lipids based on their fatty acid composition. The most prevalent compound identified in this study was phosphatidic acid (PA); digalactosyldiacylglycerol (DGDG) was the second most abundant compound. A 34:2 species was identified in PA, phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidylethanolamine (PE). The identification of lipid phosphorylation by kinases was revealed by the presence of the phosphorylated lipids. PA was metabolized to diacylglycerol pyrophosphate (DGPP) by phosphatidic acid kinase (PAK). This work establishes a correlation between lipid fatty acid composition and lipid metabolism enzymes at the beginning of tuber formation and is the first report of PAK activity in the early events of potato tuber formation.

show abstract

“…Lipid phosphorylation was allowed to proceed for 2 min at 30°C in a final volume of 100 μl. The incubation mixture was then quenched with 1.5 ml chloroform/methanol (1:2, v/v) (Racagni‐Di Palma et al 2002). Protein content of membrane samples was determined by the Bradford (1976) method with bovine albumin as standard.…”

Section: Methodsmentioning

confidence: 99%

“…Lipids were extracted from membranes as described previously (Racagni‐Di Palma et al 2002), and phospholipids were separated by TLC. Samples were spotted on silica gel plates coated with potassium oxalate solution and heated at 110°C for 60 min just before use.…”

Section: Methodsmentioning

confidence: 99%

Diacylglycerol pyrophosphate inhibits the α‐amylase secretion stimulated by gibberellic acid in barley aleurone

Racagni

Villasuso

Pasquaré

et al. 2008

Physiologia Plantarum

View full text Add to dashboard Cite

ABA plays an important regulatory role in seed germination because it inhibits the response to GA in aleurone, a secretory tissue surrounding the endosperm. Phosphatidic acid (PA) is a well-known intermediary in ABA signaling, but the role of diacylglycerol pyrophosphate (DGPP) in germination processes is not clearly established. In this study, we show that PA produced by phospholipase D (E.C. 3.1.4.4) during the antagonist effect of ABA in GA signaling is rapidly phosphorylated by phosphatidate kinase (PAK) to DGPP. This is a crucial fact for aleurone function because exogenously added dioleoyl-DGPP inhibits secretion of alpha-amylase (E.C. 3.2.1.1). Aleurone treatment with ABA and 1-butanol results in normal secretory activity, and this effect is reversed by addition of dioleoyl-DGPP. We also found that ABA decreased the activity of an Mg2+-independent, N-ethylmaleimide-insensitive form of phosphatidate phosphohydrolase (PAP2) (E.C. 3.1.3.4), leading to reduction of PA dephosphorylation and increased PAK activity. Sequence analysis using Arabidopsis thaliana lipid phosphate phosphatase (LPP) sequences as queries identified two putative molecular homologues, termed HvLPP1 and HvLPP2, encoding putative Lpps with the presence of well-conserved structural Lpp domains. Our results are consistent with a role of DGPP as a regulator of ABA antagonist effect in GA signaling and provide evidence about regulation of PA level by a PAP2 during ABA response in aleurone.

show abstract

Phosphorylation of signaling phospholipids in Coffea arabica cells

Cited by 15 publications

References 34 publications

Phosphatidylinositol kinases as regulators of GA‐stimulated α‐amylase secretion in barley (Hordeum vulgare)

Phosphatidylinositol kinases as regulators of GA‐stimulated α‐amylase secretion in barley (Hordeum vulgare)

Lipid Profiling by Electrospray Ionization Tandem Mass Spectrometry and the Identification of Lipid Phosphorylation by Kinases in Potato Stolons

Diacylglycerol pyrophosphate inhibits the α‐amylase secretion stimulated by gibberellic acid in barley aleurone

Contact Info

Product

Resources

About