Any feedback?
Literature summary for 2.4.1.14 extracted from
- Loss of the two major leaf isoforms of sucrose-phosphate synthase in Arabidopsis thaliana limits sucrose synthesis and nocturnal starch degradation but does not alter carbon partitioning during photosynthesis (2015), J. Exp. Bot., 65, 5217-5229.
Cloned(Commentary)
| Cloned (Comment) | Organism |
|---|---|
| gene sps1 or spsa1, recombinant expression in Saccharomyces cerevisiae strain CY1905, promoter-reporter gene analyses and quantitative real-time reverse transcription-PCR studies, isozyme expression patterns | Arabidopsis thaliana |
| gene sps2 or spsa2, recombinant expression in Saccharomyces cerevisiae strain CY1905, promoter-reporter gene analyses and quantitative real-time reverse transcription-PCR studies, isozyme expression patterns | Arabidopsis thaliana |
| gene sps3 or spsb, recombinant expression in Saccharomyces cerevisiae strain CY1905, promoter-reporter gene analyses and quantitative real-time reverse transcription-PCR studies, isozyme expression patterns | Arabidopsis thaliana |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| UDP-glucose + D-fructose 6-phosphate | Arabidopsis thaliana | - |
UDP + sucrose 6F-phosphate | - |
? |  |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Arabidopsis thaliana | F4JLK2 | isozyme SPSC; gene spsc or sps4 | - |
| Arabidopsis thaliana | Q8RY24 | isozyme SPSB; gene spscb or sps3 | - |
| Arabidopsis thaliana | Q94BT0 | isozyme SPSA1; gene spsa1 or sps1 | - |
| Arabidopsis thaliana | Q9FY54 | isozyme SPSA2; gene spsa2 or sps2 | - |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
| recombinant isozyme from Saccharomyces cerevisiae strain CY1905 by ammonium sulfate fractionation and two different steps of anion exchange chromatography | Arabidopsis thaliana |
Source Tissue
| Source Tissue | Comment | Organism | Textmining |
|---|---|---|---|
| anther | - |
Arabidopsis thaliana | - |
| flower bud | - |
Arabidopsis thaliana | - |
| leaf | determination of sucrose efflux from source leaves | Arabidopsis thaliana | - |
| leaf | young and mature, determination of sucrose efflux from source leaves | Arabidopsis thaliana | - |
| leaf | young and mature, isozyme AtSPSA1 is one of the major isoforms expressed in leaves. Determination of sucrose efflux from source leaves. AtSPSC constitutive expression is about 75% lower than that of AtSPSA1 | Arabidopsis thaliana | - |
| leaf | young and mature, isozyme AtSPSC is one of the major isoforms expressed in leaves. Determination of sucrose efflux from source leaves. AtSPSC expression is about 75% lower than that of AtSPSA1 | Arabidopsis thaliana | - |
| additional information | AtSPSA1 is most abundant in all tissues tested | Arabidopsis thaliana | - |
| additional information | isozyme AtSPSB shows by far the lowest expression of all isozymes in all organs analysed | Arabidopsis thaliana | - |
| additional information | no expression in stigma | Arabidopsis thaliana | - |
| petal | - |
Arabidopsis thaliana | - |
| root | - |
Arabidopsis thaliana | - |
| seed | - |
Arabidopsis thaliana | - |
| silique | - |
Arabidopsis thaliana | - |
| silique | expression only in the vascular system of the siliques, including the funiculi | Arabidopsis thaliana | - |
| stigma | - |
Arabidopsis thaliana | - |
Specific Activity [micromol/min/mg]
| Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
|---|---|---|---|
| 0.5 | - |
purified recombinant enzyme, pH 7.5, temperature not specified in the publication | Arabidopsis thaliana |
| 0.56 | - |
purified recombinant enzyme, pH 7.5, temperature not specified in the publication | Arabidopsis thaliana |
| 1.19 | - |
purified recombinant enzyme, pH 7.5, temperature not specified in the publication | Arabidopsis thaliana |
| 2.19 | - |
purified recombinant enzyme, pH 7.5, temperature not specified in the publication | Arabidopsis thaliana |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| UDP-glucose + D-fructose 6-phosphate | - |
Arabidopsis thaliana | UDP + sucrose 6F-phosphate | - |
? | |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| SPS | - |
Arabidopsis thaliana |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 7.5 | - |
assay at | Arabidopsis thaliana |
General Information
| General Information | Comment | Organism |
|---|---|---|
| malfunction | an spsa1 knock-out mutant shows a 44% decrease in leaf enzyme activity compared to the wild-type and a slight increase in leaf starch content at the end of the light period as well as at the end of the dark period. An spsa1/spsc double mutant is strongly impaired in growth and accumulated high levels of starch. This increase in starch is probably not due to an increased partitioning of carbon into starch, but is rather caused by an impaired starch mobilization during the night. Sucrose export from excised petioles harvested from spsa1/spsc double mutant plants is significantly reduced under illumination as well as during the dark period. Loss of the two major SPS isoforms in leaves limits Suc synthesis without grossly changingcarbon partitioning in favour of starch during the light period but limits starch degradation during the dark period | Arabidopsis thaliana |
| malfunction | the spsc null mutant displays reduced sucrose contents towards the end of the photoperiod and a concomitant 25% reduction in enzyme activity. In contrast, an spsa1/spsc double mutant is strongly impaired in growth and accumulated high levels of starch. This increase in starch is probably not due to an increased partitioning of carbon into starch, but is rather caused by an impaired starch mobilization during the night. Sucrose export from excised petioles harvested from spsa1/spsc double mutant plants is significantly reduced under illumination as well as during the dark period. Loss of the two major SPS isoforms in leaves limits Suc synthesis without grossly changing carbon partitioning in favour of starch during the light period but limits starch degradation during the dark period | Arabidopsis thaliana |
| metabolism | sucrose-phosphate synthase catalyses one of the rate-limiting steps in the synthesis of sucrose in plants | Arabidopsis thaliana |
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2023.1 (January 2023)
Legal
Curated at
Member of
