Tools for Cell Signaling: Synthesis of the 3-Phosphatase-Resistant 1,3,4,5-InsP4 Mimic, 1D-myo-Inositol 1,4,5-Trisphosphate 3-Phosphorothioate

The synthesis of 1D-myo-inositol 1,4,5-trisphosphate 3-phosphorothioate, a 3-phosphatase-resistant analogue of 1,3,4,5-InsP 4 is reported, and this compound is shown to elicit 45 Ca 2+ release with an EC 50 which is comparable to that of the natural metabolite, thus supporting the idea that 1,3,4,5-InsP 4 can interact with the 1,4,5-InsP 3 receptors