[51] Isolation of the plasma membrane: Membrane markers and general principles

Briskin, Donald P.; Leonard, Robert T.; Hodges, Thomas K.

doi:10.1016/0076-6879(87)48053-1

Cited by 174 publications

(118 citation statements)

References 23 publications

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“…Microsomes from developing wood samples were prepared based on the assumption that this also applies to the biosynthesis of b(1,4)-galactan in pine. All microsome preparations were characterized by measuring the activity of UDPase, an enzyme commonly used as a Golgi marker (Briskin et al, 1987). A higher UDPase activity was recorded for compression wood over normal wood in both trees sampled (Table II).…”

Section: Udpase Activity Levels In Microsome Preparationsmentioning

confidence: 99%

Exploring the Ultrastructural Localization and Biosynthesis of β(1,4)-Galactan in Pinus radiata Compression Wood

et al. 2009

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Softwood species such as pines react to gravitropic stimuli by producing compression wood, which unlike normal wood contains significant amounts of b(1,4)-galactan. Currently, little is known regarding the biosynthesis or physiological function of this polymer or the regulation of its deposition. The subcellular location of b(1,4)-galactan in developing tracheids was investigated in Pinus radiata D. Don using anti-b(1,4)-galactan antibodies to gain insight into its possible physiological role in compression wood. b(1,4)-Galactan was prominent and evenly distributed throughout the S2 layer of developing tracheid cell walls in P. radiata compression wood. In contrast, b(1,4)-galactan was not detected in normal wood. Greatly reduced antibody labeling was observed in fully lignified compression wood tracheids, implying that lignification results in masking of the epitope. To begin to understand the biosynthesis of galactan and its regulation, an assay was developed to monitor the enzyme that elongates the b(1,4)-galactan backbone in pine. A b(1,4)-galactosyltransferase (GalT) activity capable of extending 2-aminopyridine-labeled galacto-oligosaccharides was found to be associated with microsomes. Digestion of the enzymatic products using a b(1,4)-specific endogalactanase confirmed the production of b(1,4)-galactan by this enzyme. This GalT activity was substantially higher in compression wood relative to normal wood. Characterization of the identified pine GalT enzyme activity revealed pH and temperature optima of 7.0 and 20°C, respectively. The b(1,4)-galactan produced by the pine GalT had a higher degree of polymerization than most pectic galactans found in angiosperms. This observation is consistent with the high degree of polymerization of the naturally occurring b(1,4)-galactan in pine.

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Section: Udpase Activity Levels In Microsome Preparationsmentioning

confidence: 99%

Exploring the Ultrastructural Localization and Biosynthesis of β(1,4)-Galactan in Pinus radiata Compression Wood

et al. 2009

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“…To determine cytochrome c oxidase, 40 mL of the gradient fractions were used to measure the activity as described by Briskin et al (1987).…”

Section: Enzymatic Assays and Organelle Markersmentioning

confidence: 99%

The Import of S-Adenosylmethionine into the Golgi Apparatus Is Required for the Methylation of Homogalacturonan

Ibar

Orellana

2007

Plant Physiology

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S-adenosylmethionine (SAM) is the substrate used in the methylation of homogalacturonan (HGA) in the Golgi apparatus. SAM is synthesized in the cytosol, but it is not currently known how it is then transported into the Golgi. In this study, we find that HGA methyltransferase is present in Golgi-enriched fractions and that its catalytic domain faces the lumen of this organelle. This suggests that SAM must be imported into the Golgi. We performed uptake experiments using [methyl-14 C]SAM and found that SAM is incorporated into the Golgi vesicles, resulting in the methylation of polymers that are sensitive to pectinase and pectin methylesterase but not to proteases. To avoid detecting the transfer reaction, we also used [carboxyl-14 C]SAM, the uptake of which into Golgi vesicles was found to be sensitive to temperature, detergents, and osmotic changes, and to be saturable with a K m of 33 mM. Double-label uptake experiments using [methyl-3 H]SAM and [carboxyl-14 C]SAM also revealed a time-dependent increase in the 3 H to 14 C ratio, suggesting that upon transfer of the methyl group, the resulting S-adenosylhomocysteine is not accumulated in the Golgi. SAM incorporation was also found to be inhibited by S-adenosylhomocysteine, whereas UDP-GalA, UDP-GlcA, and acetyl-CoA had no effect. DIDS, a compound that inhibits nucleotide sugar transporters, also had little effect upon SAM incorporation. Interestingly, the combination of UDP-GalA 1 acetyl-CoA or UDP-GlcA 1 acetyl-CoA produced a slight increase in the uptake of SAM. These results support the idea that a SAM transporter is required for HGA biosynthesis.

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“…Additionally, ATP hydrolysis assays were performed as described by Briskin et al (1987) in 0.5 mL the reaction medium containing: 50 mM Tris-Me (pH 7.6), 250 mM sucrose, 1.0 mM DTT, 2.0 mM ATP-Na 2 , 0.1 mM (NH 4 ) 2 MoO 4 , 0.02% TritonX-100 (v/v), 300 mM NaNO 3 , 1.0 mM NaN 3 , in the presence or absence of 2.0 mM Ca(NO 3 ) 2 . The reaction was started by adding 50 µL PM vesicles.…”

Section: Determination Of Active Fe Contentmentioning

confidence: 99%

“…Isolation of plasma membrane and the measurement of H + -ATPase and Ca 2 + -ATPase activities in PMs A membrane fraction enriched in plasma membrane vesicles was prepared as described by Briskin et al (1987) with minor changes. Excised roots were homogenized (1/2, w/v) with a mortar and pestle in a cold grinding medium containing: 25 mM HEPES-Tris (pH 7.2), 250 mM mannitol, 5 mM EDTA, 5 mM ethylene glycol tetraacetic acid (EGTA), 1 mM dithiothreitol (DTT), and 1.5% (w/v) PVP.…”

Section: Determination Of Active Fe Contentmentioning

confidence: 99%

Role of exogenous nitric oxide in alleviating iron deficiency-induced peanut chlorosis on calcareous soil

Kong

Dong

et al. 2013

Journal of Plant Interactions

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This study examined the effects of exogenous nitric oxide (NO) on physiological characteristics of peanut (Arachis hypogaea L.) growing on calcareous soil. Sodium nitroprusside (SNP), a NO donor, was root application (directly; slow-release bag; slow-release capsule; slow-release particle) and foliar application. The results showed that SNP application alleviated iron (Fe) deficiency-induced chlorosis, increased the yield of peanut and increased the Fe concentration in peanut grain. SNP, especially supplied by slow-release particle improved the available Fe in soil by reducing pH of soil and increasing available Fe of soil. Furthermore, SNP application significantly increased the H + -ATPase and Fe 3 + reductase activities and increased the total Fe concentration in the leaves. Meanwhile, SNP application, especially foliar application enhanced the availability of Fe in the plant by significantly increasing the active Fe content and chlorophyll content in the leaves. In addition, SNP also increased the antioxidant activities, but decreased the superoxide anion (O 2• − ) generation rate and malondialdehyde content, which protected peanut against the Fe deficiency-induced oxidative stress. Therefore, these results support a physiological action of SNP on the availability, uptake and transport of Fe in the plant and foliar application SNP had the best effects in leaves and SNP supplied by slow-release particle had the best effects in roots. In addition, on the whole, the effects of SNP supplied by slow-release ways were better than directly supplied into the soil.

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[51] Isolation of the plasma membrane: Membrane markers and general principles

Cited by 174 publications

References 23 publications

Exploring the Ultrastructural Localization and Biosynthesis of β(1,4)-Galactan in Pinus radiata Compression Wood

Exploring the Ultrastructural Localization and Biosynthesis of β(1,4)-Galactan in Pinus radiata Compression Wood

The Import of S-Adenosylmethionine into the Golgi Apparatus Is Required for the Methylation of Homogalacturonan

Role of exogenous nitric oxide in alleviating iron deficiency-induced peanut chlorosis on calcareous soil

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