RT info:eu-repo/semantics/article T1 Calcium uptake mechanisms of mitochondria A1 Demaurex, Nicolas A1 Santo-Domingo, Jaime K1 calcium K1 mitochondria AB The ability of mitochondria to capture Ca2+ ions has important functional implications for cells, because mitochondria shape cellular Ca2+ signals by acting as a Ca2+ buffer and respond to Ca2+ elevations either by increasing the cell energy supply or by triggering the cell death program of apoptosis. A mitochondrial Ca2+ channel known as the uniporter drives the rapid and massive entry of Ca2+ ions into mitochondria. The uniporter operates at high, micromolar cytosolic Ca2+ concentrations that are only reached transiently in cells, near Ca2+ release channels. Mitochondria can also take up Ca2+ at low, nanomolar concentrations, but this high affinity mode of Ca2+ uptake is not well characterized. Recently, leucine-zipper-EF hand-containing transmembrane region (Letm1) was proposed to be an electrogenic 1:1 mitochondrial Ca2+/H+ antiporter that drives the uptake of Ca2+ into mitochondria at nanomolar cytosolic Ca2+ concentrations. In this article, we will review the properties of the Ca2+ import systems of mitochondria and discuss how Ca2+ uptake via an electrogenic 1:1 Ca2+/H+ antiport challenges our current thinking of the mitochondrial Ca2+ uptake mechanism. PB Elsevier SN 0005-2728 YR 2010 FD 2010 LK https://uvadoc.uva.es/handle/10324/65919 UL https://uvadoc.uva.es/handle/10324/65919 LA spa NO Biochim Biophys Acta, Junio 2010, vol 1797, n. 6-7, p. 907-12. DS UVaDOC RD 23-may-2024