Characteristics and Subcellular Localization of Phospholipase D and Phosphatidic Acid Phosphatase in Mung Bean Cotyledons

Herman, Eliot M.; Chrispeels, Maarten J.

doi:10.1104/pp.66.5.1001

Cited by 43 publications

(29 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is worth noting in this context that protein bodies are part of the vacuolar/lysosomal compartment of plant cells. Recent evidence shows that protein bodies are derived from vacuoles during seed maturation (5,6,27) and that they contain numerous acid hydrolases (14,17,20,26). Protein bodies therefore have an enzymic complement and function similar to that of the central vacuole of plant cells or the lysosomes of animal cells.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Assembly of storage protein oligomers in the endoplasmic reticulum and processing of the polypeptides in the protein bodies of developing pea cotyledons

Chrispeels¹,

Higgins²,

Spencer³

1982

The Journal of Cell Biology

175

View full text Add to dashboard Cite

Cotyledons of developing pea seeds (Pisurn sativum L.) were labeled with radioactive amino acids and glucosamine, and extracts were prepared and separated into fractions rich in endoplasmic reticulum (ER) or protein bodies . The time-course of synthesis of the polypeptides of legumin and vicilin and the site of their assembly into protein oligomers were studied using immunoaffinity gels and sucrose density gradients. When cotyledons were pulselabeled (1-2 h), newly synthesized legumin was present in polypeptides with Mr 60,000-65,000, and newly synthesized vicilin was present as a series of polypeptides with Mr 75,000, 70,000, 50,000, and 49,000. These radioactive polypeptides were found primarily in the ER (Chrispeels et al ., 1982, /. Cell BioL, 93 :5-14) . During a subsequent chase period, newly synthesized reserve proteins were initially present in the protein bodies in the above-named polypeptides . Between 1 and 20 h later, radioactive legumin subunits (M r 40,000 and 19,000) and smaller vicilin polypeptides (Mr 34,000, 30,000, 25,000, 18,000, 14,000, 13,000, and 12,000) appeared in the protein bodies . The appearance of these labeled polypeptides in the protein bodies was not the result of a slow transport from the ER (or cytoplasm) .Newly synthesized legumin and vicilin polypeptides were assembled into oligomers of 85 and 7S, respectively, in the ER . They appeared in the protein bodies in these oligomeric forms before the appearance of the smaller polypeptides (M r <49,000) . These results indicate that the smaller vicilin polypeptides (M r <49,000) arise by delayed posttranslational processing of some or all of the larger vicilin polypeptides . The precursors of legumin are completely processed in the protein bodies 2-3 h after their synthesis. The processing of the vicilin precursors is much slower (6-20 h) and only a fraction of the precursor molecules are processed . As a result both large (M r >49,000) and small polypeptides of vicilin accumulate in the protein bodies, whereas legumin accumulates only as polypeptides of Mr 40,000 and 19,000 .The large parenchymal cells of the cotyledons of pea (Pisum sativum L.) seeds contain 20-30% protein on a dry weight basis. The reserve proteins vicilin and legumin make up 70% of this protein. These reserve proteins are localized in protein bodies, which are spherical organelles measuring 1-3 gm in diameter consisting of an amorphous protein matrix surrounded by a limiting membrane. In mature seeds, legumin is a 12S protein (Mr 360,000) that consists of six acidic (Mr 40,000) and six basic (Mr 20,000) subunits, linked together in pairs by disulfide bridges (11). When legumin is fractionated by SDS PAGE, heterogeneity is found in both the acidic and basic subunits with three to five polypeptides in each molecular weight class .306

show abstract

Section: Discussionmentioning

confidence: 99%

“…Reserve protein polypeptides were isolated with IgG-PBE-Sepharose, fractionated by SDS PAGE, and a fluorograph was prepared . (12)(13)(14)(15)(16)(17)(18)(19)(20)(21), whereas the synthesis of the larger vicilin polypeptides (Mr 75,000 and 70,000) was most pronounced at the end of the developmental period .…”

Section: Newly Synthesized Polypeptides In the Ermentioning

confidence: 99%

Assembly of storage protein oligomers in the endoplasmic reticulum and processing of the polypeptides in the protein bodies of developing pea cotyledons

Chrispeels¹,

Higgins²,

Spencer³

1982

The Journal of Cell Biology

175

View full text Add to dashboard Cite

show abstract

“…Widespread evidence for the concerted action of PLD and PAP includes reports in mammalian literature that demonstrate DAG production from endothelialderived PC (Martin, 1988) and endogenous DAG generation in human polymorphonuclear leukocytes where DAG stimulated 5-lipoxygenase enzyme activity and function (Albert et al, 2008). In plants, isolated protein bodies from seedlings show both activities of PLD and PAP (Herman and Chrispeels, 1980), and studies of AtPLD z1 and AtPLD z2 suggest the supply of DAG for galactolipid synthesis is dependent on this pathway and also subverts phosphorus starvation (Cruz-Ramírez et al, 2006;Li et al, 2006). It has been shown that knock-down of PLDa in soybean leads to reduced PUFAs in TAG (Lee et al, 2011), implicating a flux from PC to TAG through PLD-PAP without a requirement for PDCT involvement.…”

Section: Carbon Flux Between Dag and Pc Are Highly Interconnected In mentioning

confidence: 99%

Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

Yang

Wang

et al. 2017

Plant Physiol.

View full text Add to dashboard Cite

Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase D z genes (AtPLD z1 and AtPLD z2 ) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as a component of total seed biomass and had increased 18:3 and 20:1 fatty acid levels relative to wild type. Increased DAG and decreased PC levels were examined through the kinetics of lipid assembly by [ 14 C]acetate and [ 14 C]glycerol incorporation into glycerolipids. [ 14 C]acetate was rapidly incorporated into TAG in both wild-type and overexpression lines, indicating a significant flux of nascent and elongated acyl-CoAs into the sn-3 position of TAG. Stereochemical analysis revealed that newly synthesized fatty acids were preferentially incorporated into the sn-2 position of PC, but the sn-1 position of de novo DAG and indicated similar rates of nascent acyl groups into the Kennedy pathway and acyl editing. [ 14 C]glycerol studies demonstrated PC-derived DAG is the major source of DAG for TAG synthesis in both tissues. The results emphasize that the interconversions of DAG and PC pools can impact oil production and composition.

show abstract

“…In plants PLD is known to be involved in several cellular processes but its role has not been established clearly. The enzyme is present in the protein bodies of germinating mung bean cotyledons [5] and is associated with plasma and intracellular membranes in seedling tissues of castor bean [6]. Activity changes have been observed in conjunction with water stress [7], senescence [S] and pathogenic infection [9].…”

mentioning

confidence: 99%

Study of Fatty Acid Specificity of Sunflower Phospholipase D using Detergent/Phospholipid Micelles

Abousalham¹,

Nari²,

Teissere³

et al. 1997

European Journal of Biochemistry

View full text Add to dashboard Cite

The fatty acid specificity of phospholipase D purified from germinating sunflower seeds was studied using mixed micelles with variable detergendphospholipid ratios. The main advantage of this approach is that since the substrate is integrated in the detergent micelles, comparisons can be made between the kinetic constants of a wide range of phosphatidylcholine (PtdCho) compounds with various fatty acid contents. Phospholipase D is subject to interfacial activation as it is most active on water-insoluble substrates. It is not active on sphingomyelin and only slightly on lysophosphatidylcholine. By fitting the curves based on the experimental kinetic data, the interfacial dissociation constant of phospholipase D, the maximum hydrolysis rate V , and the kinetic constant K:, were determined with the micellar substrate.The specificity of various substrates was examined by comparing the V,,,IK,B, values, and it was noted that sunflower phospholipase D is most active on medium-chain fatty PtdCho compounds. With long-chain natural phospholipids, the specificity of phospholipase D was slightly dependent on the level of fatty acid unsaturation. The pure enzyme was able to hydrolyse the sunflower phospholipids present in mixed detergent micelles but not the phospholipids integrated in the natural sunflower oil body structure. We concluded, however, that during the germination of sunflower seeds, phospholipase D might be involved in the degradation of oil bodies, since other factors present in crude seed extracts may make phospholipids accessible to the enzyme.Keywords: phospholipase D ; phospholipid; mixed micelles; sunflower oil bodies.Phospholipase D (PLD) catalyses the hydrolysis of the ester linkage between phosphatidic acid and various alcohol moieties of several phospholipid species [I-31. This enzyme is widespread in the plant and animal kingdoms. It has been reported to play an important role in signal-transduction cascades in a variety of mammalian cells [4], where it appears to be activated by various hormones and neurotransmitters and some growth factors. In plants PLD is known to be involved in several cellular processes but its role has not been established clearly. The enzyme is present in the protein bodies of germinating mung bean cotyledons [5] and is associated with plasma and intracellular membranes in seedling tissues of castor bean [6]. Activity changes have been observed in conjunction with water stress [7], senescence [S] and pathogenic infection [9]. During mung bean seed germination and seedling growth, the decrease in the phospholipid content has been correlated with an increase in PLD activity [S]. In castor bean endosperm, immunoblot analyses have shown that the amount of PLD increases during the first five days of germination. It has therefore been suggested that these activity changes may be due to metabolic reactions involving membrane phospholipids, which are essential to plant growth and development [lo]. In rice bran, crude PLD prepara- (EC 3.1.4.4). tions were found to be able to react ...

show abstract

Characteristics and Subcellular Localization of Phospholipase D and Phosphatidic Acid Phosphatase in Mung Bean Cotyledons

Cited by 43 publications

References 17 publications

Assembly of storage protein oligomers in the endoplasmic reticulum and processing of the polypeptides in the protein bodies of developing pea cotyledons

Assembly of storage protein oligomers in the endoplasmic reticulum and processing of the polypeptides in the protein bodies of developing pea cotyledons

Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

Study of Fatty Acid Specificity of Sunflower Phospholipase D using Detergent/Phospholipid Micelles

Contact Info

Product

Resources

About