Abstract
Regulation by the active form of phytochrome (PFR) and the effect of Ca2+ and calmodulin was examined with glutamate dehydrogenase (GDH) of Zea mays. A brief irradiation (5 min) to 5 day old plants with red light resulted in 5-6 fold increase in GDH activity. This effect was nullified when red light was followed immediately by far-red light. The photoreversibility showed that PFR regulates GDH activity in vivo. To the enzyme extract obtained after EGTA treatment, when Ca2+ was added in vitro, GDH was activated by 6 fold. The maximum response by Ca2+ was obtained at 80 μM. Both PAR and Ca2+ effects were found to be age dependent. The enzyme activity was inhibited by compound 48/80 in partially purified extracts and the effect was reversed by calmodulin. The purified GDH, however, was not activated directly by calmodulin; it required the presence of another protein factor which was separated by gel permeation column by HPLC. Neither anticalmodulin drugs nor addition of calmodulin had any effect on nitrate re-ductase activity.
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Claims 11
Claim · model-written summary
Brief red-light irradiation of 5 day old maize plants increased GDH activity 5-6 fold.
- Organ / stage
- 5 day old plantse1
- Treatment
- A brief irradiation (5 min) to 5 day old plants with red lighte1
- Gene
- glutamate dehydrogenasee0
- Outcome
- GDH activitye1
- Direction
- increasee1
- Value
- 5-6 folde1
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e1“A brief irradiation (5 min) to 5 day old plants with red light resulted in 5-6 fold increase in GDH activity”
Claim · model-written summary
The red-light effect on GDH activity was nullified by immediately following far-red light.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e2“This effect was nullified when red light was followed immediately by far-red light”
Claim · model-written summary
Photoreversibility indicates that phytochrome PFR regulates GDH activity in vivo.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e3“The photoreversibility showed that PFR regulates GDH activity in vivo”
Claim · model-written summary
Adding Ca2+ in vitro to the EGTA-treated enzyme extract activated GDH 6 fold.
- Treatment
- Ca2+ was added in vitroe4
- Gene
- glutamate dehydrogenasee0
- Outcome
- GDHe4
- Direction
- activatede4
- Value
- 6 folde4
- Comparator
- enzyme extract obtained after EGTA treatmente4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e4“To the enzyme extract obtained after EGTA treatment, when Ca2+ was added in vitro, GDH was activated by 6 fold”
Claim · model-written summary
The maximum response to Ca2+ was obtained at 80 μM.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e5“The maximum response by Ca2+ was obtained at 80 μM”
Claim · model-written summary
The age dependence of the PAR and Ca2+ effects on GDH was found.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e6“Both PAR and Ca2+ effects were found to be age dependent”
Claim · model-written summary
Compound 48/80 inhibited enzyme activity in partially purified extracts.
- Treatment
- compound 48/80e7
- Outcome
- enzyme activitye7
- Direction
- inhibitede7
- Setting
- partially purified extractse7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e7“The enzyme activity was inhibited by compound 48/80 in partially purified extracts”
Claim · model-written summary
Calmodulin reversed the compound 48/80 inhibition of enzyme activity.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e7“The enzyme activity was inhibited by compound 48/80 in partially purified extracts”
e2“the effect was reversed by calmodulin”
Claim · model-written summary
Purified GDH was not activated directly by calmodulin and required another protein factor.
- Treatment
- calmoduline1
- Outcome
- GDHe1
- Direction
- not activated directlye1
- Qualifier
- required the presence of another protein factore1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e1“The purified GDH, however, was not activated directly by calmodulin; it required the presence of another protein factor”
Claim · model-written summary
Anticalmodulin drugs had no effect on nitrate reductase activity.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e1“Neither anticalmodulin drugs nor addition of calmodulin had any effect on nitrate re-ductase activity”
Claim · model-written summary
Adding calmodulin had no effect on nitrate reductase activity.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“glutamate dehydrogenase (GDH) of Zea mays”
e1“Neither anticalmodulin drugs nor addition of calmodulin had any effect on nitrate re-ductase activity”
The same questions in other papers
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- no effect
- no effect
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- negative
- no effect
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See all 11 papers →radiation · molecular: metabolites · Zea mays (maize)Positive and negative results
5 papers in the same direction as this paper · 5 in the opposite direction
- no effect
- negative
- negative
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See all 11 papers →light · molecular: metabolites · Zea mays (maize)Positive and negative results
14 papers in the same direction as this paper · 15 in the opposite direction
- negative
- no effect
- no effect
26 papers more in this group
See all 30 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.