Protein Variants | Comment | Organism |
---|---|---|
additional information | generation of itpk1-1 mutants, phenotype, overview. Genetic interaction analysis of bifunctional ITPK1 (EC 2.7.1.159/EC 2.7.1.134) and IPK1 (EC 2.7.1.158) with a genetic cross between ipk1-1 and itpk1 mutants. The ipk1-1 itpk1 double mutants exhibit more severe growth defects than single mutants and those that proceeded to the reproductive stage bore aborted seeds. Common elevation of D/L-Ins(3,4,5,6)P4 in itpk1 and ipk1-1 mutants | Arabidopsis thaliana |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + 1D-myo-inositol 1,3,4-trisphosphate | Arabidopsis thaliana | - |
ADP + 1D-myo-inositol 1,3,4,5-tetrakisphosphate | - |
? | |
ATP + 1D-myo-inositol 1,3,4-trisphosphate | Arabidopsis thaliana | - |
ADP + 1D-myo-inositol 1,3,4,6-tetrakisphosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q9SBA5 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
seed | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + 1D-myo-inositol 1,3,4-trisphosphate | - |
Arabidopsis thaliana | ADP + 1D-myo-inositol 1,3,4,5-tetrakisphosphate | - |
? | |
ATP + 1D-myo-inositol 1,3,4-trisphosphate | - |
Arabidopsis thaliana | ADP + 1D-myo-inositol 1,3,4,6-tetrakisphosphate | - |
? |
Synonyms | Comment | Organism |
---|---|---|
inositol 1,3,4-trisphosphate 5/6-kinase 1 | - |
Arabidopsis thaliana |
ITPK1 | - |
Arabidopsis thaliana |
More | see also EC 2.7.1.134 | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
ATP | - |
Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
malfunction | although both ipk1-1 and itpk1 mutants exhibit decreased levels of InsP6 (phytate) and diphosphoinositol pentakisphosphate (PP-InsP5, InsP7), disruption of another ITPK family enzyme, ITPK4, which correspondingly causes depletion of InsP6 and InsP7, does not display similar phosphate-related phenotypes, which precludes these InsP species from being effectors. Notably, the level of D/L-Ins(3,4,5,6)P4 is concurrently elevated in both ipk1-1 and itpk1 mutants, which demonstrates a specific correlation with the misregulated phosphate phenotypes. The level of D/L-Ins(3,4,5,6)P4 is not responsive to phosphate starvation that instead manifests a shoot-specific increase in the InsP7 level. ITPK1 overexpression significantly decreases phosphate uptake activity, in contrast to the elevated uptake activity shown by itpk1 mutants. In addition, several PSR genes are downregulated in ITPK1-overexpressing lines compared with the wild-type (e.g. PHT1:2, SPX1, AT4, IPS1 and PAP17) | Arabidopsis thaliana |
metabolism | the kinase activity of inositol pentakisphosphate 2-kinase (IPK1) is required for phytate (inositol hexakisphosphate, InsP6) synthesis, and is indispensable for maintaining phosphate homeostasis under phosphate-replete conditions. Inositol 1,3,4-trisphosphate 5/6-kinase 1 (ITPK1) plays an equivalent role. Genetic dissection of the roles for InsP and PP-InsP biosynthesis enzymes in regulation of phosphate homeostasis, overview | Arabidopsis thaliana |
physiological function | the enzyme is required for phytate (inositol hexakisphosphate, InsP6) synthesis and involved in maintaining phosphate homeostasis under phosphate-replete conditions | Arabidopsis thaliana |