Epistasis-driven identification of SLC25A51 as a regulator of human mitochondrial NAD import

Maintenance of a mitochondrial NAD+ pool is critical for cellular life, yet the existence and identity of the transporter responsible for mitochondrial NAD+ uptake was unknown until recently. Here, the authors use genomic, genetic, and metabolomic approaches to demonstrate that SLC25A51 controls NAD+ mitochondrial levels and is the functional homolog of the yeast mitochondrial NAD+ transporter.