D-myo-Inositol-1,4,5,6-tetraphosphate (sodium salt)

D-myo-Inositol-1,4,5,6-tetraphosphate (sodium salt) (Ins(1,4,5,6)-P₄) is one of several different inositol oligophosphate isomers implicated in signal transduction. Production of Ins(1,4,5,6)-P₄ by intestinal epithelial cells increases approximately 2-14 fold, depending on the strain and incubation time, following infection with Salmonella.¹ Ins(1,4,5,6)-P₄ antagonizes epidermal growth factor (EGF) signalling through the phosphatidylinositol 3-kinase pathway.¹ Ins(1,4,5,6)-P₄ (tested as the D/L racemic mixture) is ~1,000-fold less potent than Ins(1,4,5)-P₃ at initiating Ca²⁺ release when injected into Xenopus oocytes.²

1. Eckmann, L., Rudolf, M.T., Ptasznik, A., et al. D-myo-Inositol 1,4,5,6-tetrakisphosphate produced in human intestinal epithelial cells in response to salmonella invasion inhibits phosphoinositide 3-kinase signaling pathways Proc. Natl. Acad. Sci. USA 94,14456-14460(1997).
2. DeLisle, S., Radenberg, T., Wintermantel, M.R., et al. Second messenger specificity of the inositol trisphosphate receptor: Reappraisal based on novel inositol phosphates Am. J. Physiol. 266(2 Pt 1),C429-C436(1994).