Figure 3

P2X and P2Y receptor-mediated calcium signal transduction for neural differentiation and proliferation. Activation of ionotropic P2X and metabotropic P2Y receptors trigger increases of [Ca²⁺]_i by promoting influx of extracellular calcium or by endoplasmatic reticulum calcium release, respectively. These [Ca²⁺]_i transients induce neural gene expression, by activation of some kinases or phosphatases which then stimulate transcription factors such as CREB, MEF2 and NFAT. Abbreviations: IP3, inositol 1,4,5-trisphosphate. RYR, ryanodine receptor. Gq, Gq protein. PLCβ, phospholipase C-β. PIP2, phosphatidylinositol 4,5-bisphosphate. DAG, diacylglycerol. IP3R, IP3 receptor. CaMK, Ca²⁺/calmodulin-dependent protein kinase. CREB, cAMP/Ca²⁺ response-binding element. CBP, CREB-binding protein. MEF2, myocyte enhancer factor-2. NFAT, nuclear factor of activated T-cells. PKC, protein kinase C. CaM, calmodulin. Caln, calcineurin.