Molecular Characterization of the <i>Brittle-2</i> Gene Effect on Maize Endosperm ADPglucose Pyrophosphorylase Subunits

Preiss, Jack; Danner, Stephanie; Summers, Peter S.; Morell, Matthew K.; Barton, Carolyn R.; Yang, Limei; Nieder, Matthew

doi:10.1104/pp.92.4.881

Cited by 85 publications

(57 citation statements)

References 15 publications

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“…3B). Consistent with the observation in other plants (Preiss et al, 1989;Okita et al, 1990), these results also indicate that the tomato fruit small subunits share structural homology to the small subunits in spinach leaves and potato tuber, whereas the large subunits are structurally more divergent, as revealed by the inability of the antispinach leaf AGP to cross-react with the tomato fruit large subunits (Fig. 5C).…”

Section: Multiple Forms Of Acp In Tomato Fruitsupporting

confidence: 77%

“…Proteolytic degradation of the AGP small subunit was evident during the AGP purification from maize endosperm (Plaxton and Preiss, 1987;Preiss et al, 1989). In the case of barley endosperm AGP, the small subunit was relatively resistant to proteolytic degradation but the large subunit was not, with a half-time for proteolysis at 0 to 4°C on the order of minutes, even in the presence of various protease inhibitors (Kleczkowski et al, 1993).…”

Section: Inhibition Of Protease Activity In Tomato Fruit Crude Extractmentioning

confidence: 95%

“…Comparison of cDNA sequences and immunological analysis revealed that small subunits from different sources are highly conserved, whereas the large subunits are divergent (Preiss et al, 1989;Okita et al, 1990;Smith-White and Preiss, 1992). Expression of both subunit cDNAs from potato tubers in Escherichia coli suggests that a major function of the large subunit is to modulate the regulatory properties of the native heterotetrameric enzyme, whereas that of the small subunit is catalysis (Ballicora et al, 1995).…”

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confidence: 99%

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Multiple Forms of ADP-Glucose Pyrophosphorylase from Tomato Fruit

Chen

Janes

1997

Plant Physiology

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ADP-glucose pyrophosphorylase (ACP) was purified from tomato (Lycopersicon esculentum Mill.) fruit to apparent homogeneity. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis the enzyme migrated as two close bands with molecular weights of 50,000 and 51,000. Two-dimensional polyacrylamide gel electrophoresis analysis of the purified enzyme, however, revealed at least five major protein spots that could be distinguished by their slight differences i n net charge and molecular weight. Whereas all of the spots were recognized by the antiserum raised against tomato fruit ACP holoenzyme, only three of them reacted strongly with the antiserum raised against the potato tuber ACP large subunit, and the other two spots (with lower molecular weights) reacted specifically with antisera raised against spinach leaf ACP holoenzyme and the potato tuber ACP small subunit. l h e results suggest the existente of at least three isoforms of the ACP large subunit and two isoforms of the small subunit in tomato fruit in vivo. The native molecular mass of the enzyme determined by gel filtration was 220 f 1 O kD, indicating a tetrameric structure for ACP from tomato fruit. l h e purified enzyme is very sensitive to 3-phosphoglycerate/ inorganic phosphate regulation.

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Section: Multiple Forms Of Acp In Tomato Fruitsupporting

confidence: 77%

Section: Inhibition Of Protease Activity In Tomato Fruit Crude Extractmentioning

confidence: 95%

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confidence: 99%

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Multiple Forms of ADP-Glucose Pyrophosphorylase from Tomato Fruit

Chen

Janes

1997

Plant Physiology

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“…It is generally believed that there are large and small subunits that are present in equal amounts (17). The small subunits of the enzyme from a range of sources have been found to be closely antigenically related, whereas the large subunits are much less highly antigenically conserved (17,19,20). However, two-dimensional gels have revealed the presence of more than two polypeptides in the enzyme purified from spinach leaf (13) and potato tuber (17).…”

Section: Physical Properties Of the Enzymementioning

confidence: 99%

The rb Mutation of Peas Causes Structural and Regulatory Changes in ADP Glucose Pyrophosphorylase from Developing Embryos

Hylton¹,

Smith²

1992

Plant Physiology

119

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A mutation at the rb locus of pea (Pisum sativum L.) alters the shape, reduces the starch content, and increases the lipid and sucrose contents of the seed. These effects are probably all consequences of a reduction of up to 40-fold in the maximum catalytic activity of ADP glucose pyrophosphorylase in the developing embryo of the mutant relative to the wild type. We have investigated how the mutation brings about this reduction in activity. The purified enzyme from mutant embryos has a specific activity about 10-fold lower than that from wild-type embryos, and it is much more sensitive to the effectors inorganic phosphate and 3-phosphoglycerate than the wild-type enzyme. Both wild-type and mutant enzymes consist of polypeptides of around 50 kilodaltons. One of the polypeptides of the purified wild-type enzyme is missing from the mutant enzyme. We deduce that in the wild-type embryo this protein may interact with other subunits to confer a high specific activity and a low susceptibility to effectors on the enzyme.The aim of this work was to investigate the effect of a mutation at the rb locus of peas (Pisum sativum L.) on the activity of ADP glucose pyrophosphorylase in developing embryos. The mutation has multiple phenotypic effects on the seed. It changes its shape from round to wrinkled, reduces starch content from 50 to about 25% of the final dry weight, and increases sucrose and lipid contents from 5 to 9% and 2 to 4%, respectively (4,8,25). These effects are very similar to those of the well-characterized mutation at the r locus of pea, which are consequences of a reduction in the rate of starch synthesis in the developing embryo resulting from a reduced activity of starch-branching enzyme (1,8,22). We have shown previously that the mutation at the rb locus results in a 10-to 40-fold reduction in the activity of ADP glucose pyrophosphorylase during embryo development, and has no effect on the activities of other enzymes catalyzing the conversion of sucrose to starch (23). This reduction almost certainly accounts for the reduced rate of starch synthesis (23) and, hence, the reduced starch content of the embryo. By analogy with the effects of the mutation at the r locus, it is likely that the reduced rate of starch synthesis accounts for many, if not all, of the other phenotypic effects. To discover '

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“…Western blot analyses of maize endosperm crude extracts or of partially purified maize ADPglucose pyrophosphorylase showed that antibodies prepared against the purified spinach leaf ADPglucose pyrophosphorylase 51 kD or 54 kD subunits cross reacted with the 54 kD and 60 kD maize subunits, respectively (21). The cross reaction with the antibody prepared against the spinach leaf 54 kD subunit gave a weaker reaction with the corresponding 60 kD subunit of the maize enzyme than the reaction observed with the anti 51 kD spinach antibody and the corresponding maize endosperm enzyme 54 kD subunit.…”

Section: Structural Analysis Of Adpglucose Pyrophosphorylasementioning

confidence: 99%

The Subunit Structure of Potato Tuber ADPglucose Pyrophosphorylase

Okita¹,

Nakata²,

Anderson³

et al. 1990

Plant Physiol.

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178

125

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ADPglucose pyrophosphorylase has been extensively purified from potato (Solanum tuberosum L.) tuber tissue to study its structure. By employing a modified published procedure (JR Sowokinos, J Preiss [1982] Plant Physiol 69: 1459-1466) together with Mono 0 chromatography, a near homogeneous enzyme preparation was obtained with substantial improvement in enzyme yield and specific activity. In single dimensional sodium dodecyl sulfate polyacrylamide gels, the enzyme migrated as a single polypeptide band with a mobility of about 50,000 daltons. Analysis by two-dimensional polyacrylamide gel electrophoresis, however, revealed the presence of two types of subunits which could be distinguished by their slight differences in net charge and molecular weight. The smaller potato tuber subunit was recognized by antiserum prepared against the smaller spinach leaf 51 kilodalton ADPglucose pyrophosphorylase subunit. In contrast, the anti-54 kilodalton raised against the spinach leaf subunit did not significantly react to the tuber enzyme subunits. The results are consistent with the hypothesis that the potato tuber ADPglucose pyrophosphorylase is not composed of a simple homotetramer as previously suggested, but is a product of two separate and distinct subunits as observed for the spinach leaf and maize enzymes.ADPglucose pyrophosphorylase (ATP: a-glucose-1-P adenylyl-transferase, EC 2.7.7.27) catalyzes an important regulatory step in the biosynthesis of starch and glycogen in plants and bacteria, respectively (2, 16-20). This enzyme mediates the synthesis of ADPglucose and PPi from ATP and glucose-I-P; the product, ADPglucose, serving as the glucosyl donor in a-glucan synthesis. Both the plant and bacterial enzymes are subject to allosteric regulation by small effector molecules 'Supported in part by grants from the

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Molecular Characterization of the Brittle-2 Gene Effect on Maize Endosperm ADPglucose Pyrophosphorylase Subunits

Cited by 85 publications

References 15 publications

Multiple Forms of ADP-Glucose Pyrophosphorylase from Tomato Fruit

Multiple Forms of ADP-Glucose Pyrophosphorylase from Tomato Fruit

The rb Mutation of Peas Causes Structural and Regulatory Changes in ADP Glucose Pyrophosphorylase from Developing Embryos

The Subunit Structure of Potato Tuber ADPglucose Pyrophosphorylase

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