Abstract
Several possible control mechanisms for CTP:choline-phosphate cytidylyltransferase (EC 2.7.7.15) activity in pea (Pisum sativum L.) stems were investigated. Indol-3-ylacetic acid (IAA) treatment of the pea stems decreased total cytidylyltransferase activity but did not affect its subcellular distribution. Oleate (2 mM) caused some stimulation of enzyme activity by release of activity from the microsomal fraction into the cytosol, but neither phosphatidylglycerol nor monoacyl phosphatidylethanolamine had an effect on activity or subcellular distribution. A decrease in soluble cytidylyltransferase protein concentrations was found in IAA-treated pea stems, but this was not sufficient to account for all of the decrease in cytidylyltransferase activity. A 50% inhibition of enzyme activity could be obtained with 0.2 mM-CMP, which indicated possible allosteric regulation. Similar inhibition was obtained with 1.5 mM-ATP, but other nucleotides had no effect. The cytidylyltransferase enzyme protein was not directly phosphorylated, and the inhibition with 1.5 mM-ATP occurred with the purified enzyme, thus excluding an obligatory mediation via a modulator protein. The results indicate that the cytosolic form of cytidylyltransferase is the most important in pea stem tissue and that the decrease in cytidylyltransferase activity in IAA-treated material appears to be brought about by several methods.
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Claims 10
Claim · model-written summary
IAA decreased total cytidylyltransferase activity in pea stems.
- Taxon
- pea
Lathyrus oleraceuse0 - Treatment
- Indol-3-ylacetic acid (IAA) treatmente0
- Gene
- cytidylyltransferasee0
- Outcome
- total cytidylyltransferase activitye0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Indol-3-ylacetic acid (IAA) treatment of the pea stems decreased total cytidylyltransferase activity but did not affect its subcellular distribution.”
Claim · model-written summary
IAA did not affect the subcellular distribution of cytidylyltransferase.
- Taxon
- peaLathyrus oleraceuse0
- Treatment
- Indol-3-ylacetic acid (IAA) treatmente0
- Gene
- cytidylyltransferasee0
- Outcome
- subcellular distributione0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Indol-3-ylacetic acid (IAA) treatment of the pea stems decreased total cytidylyltransferase activity but did not affect its subcellular distribution.”
Claim · model-written summary
Oleate stimulated cytidylyltransferase activity through release from microsomes into cytosol.
- Treatment
- Oleate (2 mM)e0
- Outcome
- enzyme activitye0
- Direction
- stimulatione0
- Qualifier
- release of activity from the microsomal fraction into the cytosole0
Not reportedTaxonComparator
Verbatim
e0“Oleate (2 mM) caused some stimulation of enzyme activity by release of activity from the microsomal fraction into the cytosol”
Claim · model-written summary
Neither phosphatidylglycerol nor monoacyl phosphatidylethanolamine affected enzyme activity or distribution.
- Treatment
- phosphatidylglycerol nor monoacyl phosphatidylethanolaminee0
- Outcome
- activity or subcellular distributione0
- Direction
- had an effecte0
Not reportedTaxonComparator
Verbatim
e0“neither phosphatidylglycerol nor monoacyl phosphatidylethanolamine had an effect on activity or subcellular distribution”
Claim · model-written summary
IAA decreased soluble cytidylyltransferase protein concentration in pea stems.
- Taxon
- peaLathyrus oleraceuse0
- Treatment
- IAA-treatede0
- Outcome
- soluble cytidylyltransferase protein concentrationse0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A decrease in soluble cytidylyltransferase protein concentrations was found in IAA-treated pea stems”
Claim · model-written summary
CMP inhibited cytidylyltransferase activity by 50% at 0.2 mM.
Not reportedTaxonComparator
Verbatim
e0“A 50% inhibition of enzyme activity could be obtained with 0.2 mM-CMP”
Claim · model-written summary
ATP at 1.5 mM similarly inhibited enzyme activity, including in purified enzyme.
Not reportedTaxonComparator
Verbatim
e0“Similar inhibition was obtained with 1.5 mM-ATP”
Claim · model-written summary
Other nucleotides had no effect on enzyme activity.
Not reportedTaxonComparator
Verbatim
e0“other nucleotides had no effect”
Claim · model-written summary
Cytidylyltransferase protein was not directly phosphorylated.
Not reportedTaxon
Verbatim
e0“The cytidylyltransferase enzyme protein was not directly phosphorylated”
Claim · model-written summary
The cytosolic cytidylyltransferase form was judged most important in pea stem tissue.
- Taxon
- peaLathyrus oleraceuse0
- Gene
- cytidylyltransferasee0
- Outcome
- the most importante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the cytosolic form of cytidylyltransferase is the most important in pea stem tissue”
The same questions in other papers
indole-3-acetic acid · physiology: enzyme activity · Lathyrus oleraceus (pea)Positive and negative results
1 paper in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
2 papers more in this group
See all 6 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.