PI4P is phosphorylated to PI(4,5)P2 by PIP5K1A-C at the plasma membrane At the plasma membrane, phosphatidylinositol-4-phosphate 5-kinase type-1 alpha (PIP5K1A), beta (PIP5K1B), and gamma (PIP5K1C) phosphorylate phosphatidylinositol 4-phosphate (PI4P) to produce phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2).<br><br>The following lists the above proteins with their corresponding literature references: PIP5K1A (Halstead et al. 2006, Zhang et al. 1997), PIP5K1B (Zhang et al. 1997), and PIP5K1C (Di Paolo et al. 2002).<br><br>This reaction is of particular interest because its regulation by small GTPases of the RHO and ARF families, not yet annotated here, ties the process of phosphatidylinositol phosphate biosynthesis to regulation of the actin cytoskeleton and vesicular trafficking, and hence to diverse aspects of cell motility and signalling (Oude Weernink et al., 2004, 2007). Authored: Williams, MG, 2011-10-18 EC Number: 2.7.1.68 Edited: Williams, MG, 2011-08-12 Pubmed12422219 Pubmed15464023 Pubmed16979564 Pubmed17245604 Pubmed9211928 Reactome Database ID Release 431676082 Reactome, http://www.reactome.org ReactomeREACT_120952 Reviewed: Wakelam, Michael, 2012-05-14