| abstract |
Steroidogenic acute regulatory protein (StAR), a mitochondrial protein, required for stress response, reproduction, and male fetal sexual differentiation, is not in its final resting position in the matrix, but in the outer mitochondrial membrane (OMM) Have been shown to exert their activity temporarily, and their OMM residence time and activity are regulated by their rate of mitochondrial transport. This may be the first time a mitochondrial protein has exerted its biological activity in a compartment other than its final destination. This unique system, which allows steroidogenic cells to start and stop high levels of steroid production within minutes, allows for rapid regulation of serum steroid hormone concentrations, and thus with the StAR protein leader sequence It can be manipulated by changing the binding of its receptor on the OMM. |