The calcium dependent ATP-Mg/Pi mitochondrial carrier is a target of glucose-induced calcium signalling in Saccharomyces cerevisiae.
Cavero S, Traba J, Del Arco A, Satrústegui J
Biochemical Journal (2005)
Category: mitochondria-transport ¤ Added: Nov 04, 2005 ¤ Rating: ◊◊
Sal1p is a mitochondrial protein that belongs to the SCaMC (Short Calcium-binding Mitochondrial Carriers) subfamily of mitochondrial carriers. The presence of calcium binding motifs facing the extramitochondrial space allows the regulation of the transport activity of these carriers by cytosolic calcium and provides a new mechanism to transduce calcium signals in mitochondria without the requirement of calcium entry in the organelle. We have studied its transport activity, finding that it is a carboxyatractyloside-resistant ATP-Mg carrier. Mitochondria from a disruption mutant of SAL1 have a 50% reduction in the uptake of ATP. We have also found a clear stimulation of ATP transport activity by calcium, with an S 0,5 of about 30 muM. Our results also suggest that Sal1p is a target of the glucose-induced calcium signal which is non essential in wild type cells but becomes essential for transport of ATP into mitochondria in yeast lacking ATP/ADP translocases.