Mitochondrial Calcium Homeostasis: Mechanisms and Molecules

Despite the early characterisation of Ca 2+ fluxes in isolated mitochondria and the ability of this ion to up‐regulate dehydrogenases of the Krebs cycle, the low affinity of the organelle uptake pathways was a long‐standing obstacle to the recognition of a physiological role for mitochondrial Ca 2+ uptake. This review begins with a historical account of the main results that proved the contrary and provides a brief description of mitochondrial Ca 2+ signals. Then, it discusses the characteristics of Ca 2+ regulation of mitochondrial function. Finally, it summarizes recent discoveries on structural aspects of mitochondrial reticulum and its connections to signalling partners such as the endoplasmic reticulum or the plasma membrane.