Yeast mitochondria import ATP through the calcium-dependent ATP-Mg/Pi carrier Sal1p, and are ATP consumers during aerobic growth in glucose.

Sal1p, a novel Ca2+-dependent ATP-Mg/Pi carrier, is essential in yeast lacking all adenine nucleotide translocases. By targeting luciferase to the mitochondrial matrix to monitor mitochondrial ATP levels, we show in isolated mitochondria that both ATP-Mg and free ADP are taken up by Sal1p with a K(m) of 0.20 +/- 0.

SLC41A1 is a novel mammalian Mg2+ carrier.

The molecular biology of mammalian magnesium transporters and their interrelations in cellular magnesium homeostasis are largely unknown. Recently, the mouse SLC41A1 protein was suggested to be a candidate magnesium transporter with channel-like properties when overexpressed in Xenopus laevis oocytes. Here, we demonstrate that human SLC41A1 overexpressed in HEK293 cells forms protein complexes and locates to the plasma membrane without, however, giving rise to any detectable magnesium currents during whole cell patch clamp experiments.