PI5P is phosphorylated to PI(4,5)P2 by PIP4K2 dimers in the nucleus

Stable Identifier
Reaction [transition]
Homo sapiens
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In the nucleus, phosphatidylinositol 5-phosphate (PI5P) is phosphorylated to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) mainly by phosphatidylinositol-5-phosphate 4-kinase type-2 beta (PIP4K2B). In the nucleus, PIP4K2B predominantly functions as a homodimer or a heterodimer with PIP4K2A. A low level of PIP4K2A homodimers can also be found in the nucleus. Nuclear localization of PIP4K2C has not been examined but is assumed to be possible, at least through formation of heterodimers with PIP4K2B (Ciruela et al. 2000, Jones et al. 2006, Bultsma et al. 2010). Under conditions of cellular stress, nuclear PIP4K2B can be phosphorylated by p38 MAP kinases, resulting in PIP4K2B inactivation. The putative p38 target site, serine residue S326 of PIP4K2B, is conserved in PIP4K2A, but the role and mechanism of p38-mediated regulation of PIP4K2 isoforms has not been studied in detail (Jones et al. 2006).

Literature References
PubMed ID Title Journal Year
16949365 Nuclear PtdIns5P as a transducer of stress signaling: an in vivo role for PIP4Kbeta

Jones, DR, D'Santos, CS, Bultsma, Y, Heck, AJ, Keune, WJ, Halstead, JR, Divecha, N, Mohammed, S, Elouarrat, D

Mol. Cell 2006
10698683 Nuclear targeting of the beta isoform of type II phosphatidylinositol phosphate kinase (phosphatidylinositol 5-phosphate 4-kinase) by its alpha-helix 7

Ciruela, A, Irvine, RF, Hinchliffe, KA, Divecha, N

Biochem. J. 2000
20583997 PIP4Kbeta interacts with and modulates nuclear localization of the high-activity PtdIns5P-4-kinase isoform PIP4Kalpha

Bultsma, Y, Keune, WJ, Divecha, N

Biochem. J. 2010
Catalyst Activity

1-phosphatidylinositol-5-phosphate 4-kinase activity of PIP4K2 dimers [nucleoplasm]

Orthologous Events
Cross References
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