IUBMB Enzyme Nomenclature


Accepted name: inositol-pentakisphosphate 2-kinase

Reaction: ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate = ADP + 1D-myo-inositol hexakisphosphate

Other name(s): IP5 2-kinase; Gsl1p; Ipk1p; Plc1p; inositol polyphosphate kinase; inositol 1,3,4,5,6-pentakisphosphate 2-kinase; Ins(1,3,4,5,6)P5 2-kinase

Systematic name: ATP:1D-myo-inositol 1,3,4,5,6-pentakisphosphate 2-phosphotransferase

Comments: The enzyme can also use Ins(1,4,5,6)P4 [2] and Ins(1,4,5)P3 [3] as substrate. Inositol hexakisphosphate (phytate) accumulates in storage protein bodies during seed development and, when hydrolysed, releases stored nutrients to the developing seedling before the plant is capable of absorbing nutrients from its environment [5].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. York, J.D., Odom, A.R., Murphy, R., Ives, E.B. and Wente, S.R. A phospholipase C-dependent inositol polyphosphate kinase pathway required for efficient messenger RNA export. Science 285 (1999) 96-100. [PMID: 10390371]

2. Phillippy, B.Q., Ullah, A.H. and Ehrlich, K.C. Purification and some properties of inositol 1,3,4,5,6-Pentakisphosphate 2-kinase from immature soybean seeds. J. Biol. Chem. 269 (1994) 28393-28399. [PMID: 7961779]

3. Ongusaha, P.P., Hughes, P.J., Davey, J. and Michell, R.H. Inositol hexakisphosphate in Schizosaccharomyces pombe: synthesis from Ins(1,4,5)P3 and osmotic regulation. Biochem. J. 335 (1998) 671-679. [PMID: 9794810]

4. Miller, A.L., Suntharalingam, M., Johnson, S.L., Audhya, A., Emr, S.D. and Wente, S.R. Cytoplasmic inositol hexakisphosphate production is sufficient for mediating the Gle1-mRNA export pathway. J. Biol. Chem. 279 (2004) 51022-51032. [PMID: 15459192]

5. Stevenson-Paulik, J., Odom, A.R. and York, J.D. Molecular and biochemical characterization of two plant inositol polyphosphate 6-/3-/5-kinases. J. Biol. Chem. 277 (2002) 42711-42718. [PMID: 12226109]

[EC created 2006]

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