InterPro domain: IPR017163

This entry represents a group of plant-type phosphatidylinositol-4-phosphate 5-kinases (PIP5K; 2.7.1.68 ), which play an essential role in coordinating plant growth, especially in response to environmental factors. This enzyme phosphorylates phosphatidylinositol-4-phosphate to produce phosphatidylinositol-4,5-bisphosphate as a precursor of two second messengers, inositol-1,4,5-triphosphate and diacylglycerol, and as a regulator of many cellular proteins involved in signal transduction and cytoskeletal organisation. This enzyme is involved in flowering, and may suppress floral initiation by modifying the expression of genes related to floral induction. It appears to be stress-induced [ 1 , 2 ].

1. A gene encoding phosphatidylinositol-4-phosphate 5-kinase is induced by water stress and abscisic acid in Arabidopsis thaliana. Plant J. 15, 563-8
2. PIP5K9, an Arabidopsis phosphatidylinositol monophosphate kinase, interacts with a cytosolic invertase to negatively regulate sugar-mediated root growth. Plant Cell 19, 163-81