Cloned (Comment) | Organism |
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gene GPAT9, recombinant expression in Saccharomyces cerevisiae strain gat1DELTA (Matalpha, his3C1, leu2C0, lys2C0, ura3C0, YKR067w::kanMX4), quantitative real-time RT-PCR analysis | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | generation of two GPAT9 overexpression vectors, i.e. constitutive (GPAT9-OE) and seed-specific (GPAT9-SS-OE) vectors, respectively, and of two GPAT9 RNAi vectors, i.e. constitutive (GPAT9-RNAi) and seed-specific (GPAT9-SS-RNAi) vectors, respectively. To generate GPAT9 overexpression constructs, the GPAT9 coding sequence is inserted between the constitutive tobacco tCUP3 promoter and Pisum sativum ribulose-1,5-bisphosphate carboxylase transcriptional terminator (rbcS-t) to generate the GPAT9-OE vector, or between the seed-specific Brassica napus Napin promoter and rbcS-t transcriptional terminator to produce the GPAT9-SS-OE vector. The GPAT9 RNAi fragments are inserted in opposite orientations between the constitutive tCUP3 promoter and intronic spacer from the pHannibal plasmid, and rbcS-t transcriptional terminator and intronic spacer, respectively. These same sense and antisense GPAT9 fragments are also inserted between the seed-specific Phaseolus vulgaris beta-phaseolin promoter and pHannibal intronic spacer, and the beta-phaseolin transcriptional terminator and intronic spacer, respectively, in a pPZP-RSC1 background. Overexpression and down-regulation of GPAT9 in Arabidopsis thaliana results in changes in seed size, as well as seed oil content and composition, phenotypes, overview. Overexpression of GPAT9 in GPAT9-OE lines results in increased seed oil content, downregulation of this gene in GPAT9-RNAi lines yields significant decreases in seed oil content. No significant differences are noted in seed yields between either T3 homozygous GPAT9-OE and wild-type lines, or GPAT9-RNAi and wild-type. Altering the constitutive expression of GPAT9 in Arabidopsis enhances production of lipid droplets in pollen grains | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
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Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
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acyl-CoA + sn-glycerol 3-phosphate | Arabidopsis thaliana | - |
CoA + 1-acyl-sn-glycerol 3-phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q8GWG0 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
cauline leaf | - |
Arabidopsis thaliana | - |
embryo | - |
Arabidopsis thaliana | - |
flower | - |
Arabidopsis thaliana | - |
flower bud | - |
Arabidopsis thaliana | - |
leaf | - |
Arabidopsis thaliana | - |
additional information | GPAT9 is constitutively expressed. The expression pattern is relatively broad. Comparable levels of GPAT9 expression are noted in the majority of tissues tested, including seedlings, rosette and cauline leaves (28 DAP), stems, roots, floral buds, open flowers, pollen, and siliques/seeds/embryos at various developmental stages. The highest levels of expression appears to be evident in leaves and developing siliques [at about 9 d after flowering (DAF)] | Arabidopsis thaliana | - |
pollen | high expression level | Arabidopsis thaliana | - |
root | - |
Arabidopsis thaliana | - |
rosette leaf | - |
Arabidopsis thaliana | - |
seed | - |
Arabidopsis thaliana | - |
seedling | - |
Arabidopsis thaliana | - |
silique | - |
Arabidopsis thaliana | - |
stem | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
acyl-CoA + sn-glycerol 3-phosphate | - |
Arabidopsis thaliana | CoA + 1-acyl-sn-glycerol 3-phosphate | - |
? | |
additional information | regiospecificity of GPAT9, the majority of the acylation reactions catalyzed by this enzyme takes place at the sn-1 position rather than the sn-2 position (5.3:1 ratio) | Arabidopsis thaliana | ? | - |
- |
Synonyms | Comment | Organism |
---|---|---|
GPAT9 | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
assay at | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
malfunction | alteration of constitutive GPAT9 expression has no obvious effects on surface lipid biosynthesis. But overexpression and downregulation of GPAT9 in Arabidopsis thaliana results in changes in seed size, as well as seed oil content and composition. Altering the constitutive expression of GPAT9 in Arabidopsis enhances production of lipid droplets in pollen grains. Knockout of gpat9 has been shown to result in a male gametophytic lethality phenotype | Arabidopsis thaliana |
metabolism | the preference of GPAT9 for acyl-CoA as its substrate, and its sn-1 regio-specificity, provide support that it plays an important role in the Kennedy pathway of glycerolipid biosynthesis | Arabidopsis thaliana |
physiological function | enzyme GPAT9 has a role for GPAT9 in seed oil biosynthesis and contributes to the biosynthesis of both polar lipids and triacylglycerol (TAG) in developing leaves, as well as lipid droplet production in developing pollen grains. GPAT9 exhibits sn-1 acyltransferase activity with high specificity for acyl-coenzyme A, thus providing further evidence that this GPAT is involved in storage lipid biosynthesis | Arabidopsis thaliana |