In eukaryotic cells, mitochondria are involved in many cellular processes including energy production, apoptosis, ion homeostasis, and the metabolism of glucose, lipids, and amino acids [10] . Although mitochondria possess their own DNA, it is estimated that at least 98% of the 1,500-2,000 mitochondrial proteins are encoded by nuclear genes and shuttled posttranslationally into the mitochondria [11, 12] . In addition, the majority of human mt disorders are known to be related with nuclear genome defects [13] . Thus, compiling a comprehensive list of mt proteins is essential to understand mitochondrial biogenesis and pathology. Large-scale approaches such as mass spectrometry (MS)-based proteomics [14] , epitope tagging combined with microscopy [15] , genome-wide predictions of protein subcellular localizations [16] , and comparative genomics analyses [17, 18, 19] have revealed the localization of the mt protein inventory.