Genetically targeted calcium sensors enhance the study of organelle function in living cells

1, Understanding the regulation of calcium (Ca2+), the most common of the m ineral ions within the human body; has always been of extreme interest to p hysiologists. While the importance of Ca2+ in contributing to physiological events through regulation of levels has been significantly established, se ldom is consideration given to the intricacies of this ion and its mechanic s in producing such diverse physiological responses in different regions of the cell, 2, The present review will summarize new methodologies used in our laborato ries for the study of two major intracellular organelles, mitochondria and the nucleus, These techniques are based predominantly on the use of molecul ar biological approaches to both create and then target protein-based senso r molecules to specific intracellular locations. 3, The regulation of Ca2+ in the mitochondria and nucleus is of particular interest to us because of the central involvement of these organelles in: ( i) cardiac cell responses during ischaemia/reperfusion; and (ii) the contro l of gene expression, respectively.