Inositolpentakisphosphate 2-kinase (IPPK), also known as IP52K, phosphorylates inositol 1,3,4,5,6-pentakisphosphate (I(1,3,4,5,6)P5) to inositol 1,2,3,4,5,6-hexakisphosphate (IP6) (Verbski et al. 2002, Brehm et al. 2007, Choi et al. 2007).
inositol pentakisphosphate 2-kinase activity of IPPK [cytosol]