Cellular pan-chain acyl-CoA profiling reveals SLC25A42/SLC25A16 in mitochondrial CoA import and metabolism

The essential cofactor coenzyme A (CoASH) and its thioester derivatives (acyl-CoAs) have pivotal roles in cellular metabolism. However, the mechanism by which different acyl-CoAs are accurately partitioned into different subcellular compartments to support site-specific reactions, and the physiological impact of such compartmentalization, remain poorly understood. Here, we report an optimized liquid chromatography–mass spectrometry-based pan-chain acyl-CoA extraction and profiling method that enables a robust detection of 33 cellular and 23 mitochondrial acyl-CoAs from cultured human cells. We reveal that SLC25A16 and SLC25A42 are critical for mitochondrial import of free CoASH. This CoASH import process supports an enriched mitochondrial CoA pool and CoA-dependent pathways in the matrix, including the high-flux TCA cycle and fatty acid oxidation. Despite a small fraction of the mitochondria-localized CoA synthase COASY, de novo CoA biosynthesis is primarily cytosolic and supports cytosolic lipid anabolism. This mitochondrial acyl-CoA compartmentalization enables a spatial regulation of anabolic and energy-related catabolic processes, which promises to shed light on pathophysiology in the inborn errors of CoA metabolism. By developing a method that allows detection of transient, low-abundance acyl-CoA species, Liu et al. provide a thorough characterization of coenzyme A dynamics and subcellular partitioning.