The renaissance of mitochondrial calcium transport.
Although the capacity of mitochondria for accumulating Ca2+ down the electrical gradient generated by the respiratory chain has been known for over three decades, the physiological significance of this phenomenon has been re-evaluated only recently. Indeed, it was long believed that the low affinity of the mitochondrial Ca2+ transporters would allow significant uptake only in conditions of cellular Ca2+ overload. Conversely, the direct measurement of [Ca2+] in the mitochondrial matrix revealed major [Ca2+] increases upon agonist stimulation. In this review, we will summarize: (a) the mechanisms that allow this large response, reconciling the biochemical properties of the transporters and the large amplitude of the mitochondrial [Ca2+] rises, and (b) the biological role of mitochondrial Ca2+ signalling, that encompasses the regulation of mitochondrial function and the modulation of the spatio-temporal pattern of cytosolic [Ca2+] increases.
Pozzan
T
T
Department of Biomedical Sciences and CNR Center for the Study of Biomembranes, University of Padova, Italy. pozzant@civ.bio.unipd.it
Rizzuto
R
R
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D017136:Ion Transport; D008928:Mitochondria / Q000378:metabolism*
D002118:Calcium