Inositol 1,4,5-trisphosphate (IP3)-induced intracellular Ca2+ release is an excitable process which mediates the effects of activated hormone and neurotransmitter pathways. Ca2+-induced Ca2+ release (CICR) from the IP3-bound IP3 receptor (IP3R) is the fundamental property which generates propagating Ca2+ waves when coupled to Ca2+ diffusion. These waves annihilate upon collision primarily due to Ca2+ inhibition of Ca2+ release at high Ca2+ concentrations. Since intracellular Ca2+ release is clearly controlled by Ca2+ feedback mechanisms, by necessity, any cellular process which binds, sequesters, and/or pumps intracellular Ca2+ will affect the dynamics of Ca2+ signalling. My talk will focus on the molecular control of Ca2+ signalling by Ca2+ binding proteins (CaBPs), Ca2+-ATPases, and mitochondria in Xenopus oocytes.