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Literature summary for 2.7.1.158 extracted from

  • Kuo, H.; Hsu, Y.; Lin, W.; Chen, K.; Munnik, T.; Brearley, C.; Chiou, T.
    Arabidopsis inositol phosphate kinases IPK1 and ITPK1 constitute a metabolic pathway in maintaining phosphate homeostasis (2018), Plant J., 95, 613-630 .
    View publication on PubMed
Search for more literature for 2.7.1.158

Protein Variants

Protein Variants Comment Organism
D368A site-directed mutagenesis, mutant IPK1D368A shows loss of kinase activity in vitro Arabidopsis thaliana
K168A site-directed mutagenesis, mutant IPK1K168AD shows loss of kinase activity in vitro Arabidopsis thaliana
additional information generation of ipk1-1 mutants, phenotype, overview. Genetic interaction analysis of ITPK1 (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

Metals/Ions Comment Organism Structure
Mg2+ required Arabidopsis thaliana

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate Arabidopsis thaliana
-
 ADP + 1D-myo-inositol hexakisphosphate
-
 ?

Organism

Organism UniProt Comment Textmining
Arabidopsis thaliana Q93YN9
-
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate
-
 Arabidopsis thaliana ADP + 1D-myo-inositol hexakisphosphate
-
 ?

Synonyms

Synonyms Comment Organism
inositol pentakisphosphate 2-kinase
-
 Arabidopsis thaliana
Ipk1
-
 Arabidopsis thaliana

Cofactor

Cofactor Comment Organism Structure
ATP
-
 Arabidopsis thaliana

General Information

General Information Comment Organism
malfunction in contrast to wild-type IPK1, which is able to restore the phosphate content of the ipk1-1 mutant to wild-type level, both kinase-inactive IPK1 forms fail to complement excessive phosphate accumulation and PSR gene activation in ipk1-1. 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. Misregulation of phosphate homeostasis in ipk1-1 is not caused by defective InsP6-mediated mRNA export. Neither of the kinase-inactive IPK1 mutants K168A and D368A complement the PSR-like RSA phenotypes (i.e. reduced primary root and enhanced lateral root growth) of ipk1-1 mutant. In addition to the decreased InsP6 level, levels of InsP7 and InsP8 are also reduced in ipk1-1 mutants Arabidopsis thaliana
metabolism genetic dissection of the roles for InsP and PP-InsP biosynthesis enzymes in regulation of phosphate homeostasis, overview Arabidopsis thaliana
physiological function 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. In addition to regulating the phosphate content, the kinase activity of IPK1 is also required for root system architecture Arabidopsis thaliana