Rapid changes of mitochondrial Ca2+ revealed by specifically targeted recombinant aequorin
Key findings
Demonstrated that the N-terminal targeting sequence (MTS) of cytochrome c oxidase subunit VIII (COX8) efficiently directs heterologous proteins to the mitochondrial matrix in mammalian cells. Fused the COX8 MTS to aequorin to measure mitochondrial calcium. The COX8 MTS (first 25 aa) became the standard mitochondria-targeting sequence for engineered constructs.