Mitochondria host a number of reductive biosynthetic pathways and rely on extensive metabolite exchanges with the cytosol to support cellular anabolic metabolism. Mitochondrial iron-sulfur cluster (Fe-S) biogenesis is essential for multiple cellular functions, and its disruption causes various inborn genetic diseases. How mammalian cells regulate Fe-S biogenesis remains incompletely understood. Here, mitochondria-focused CRISPR screening and DepMap-based gene co-essentiality analysis consistently reveal that components of the carrier translocase of the inner mitochondrial membrane (TIM22) complex, including TIMM29, are selectively required for Fe-S biogenesis. Mechanistically, loss of TIM22 complex function reduced iron transporter presence on mitochondria, thereby impairing iron uptake from the cytosol. Reconstituting mitochondrial iron level was sufficient to restore Fe-S biogenesis and proliferation of TIMM29-deficient cells or rescue the embryonic development of timm29-deficient zebrafish. Thus, a primary function of the TIM22 carrier translocase is to facilitate transporter-mediated iron uptake required for Fe-S biogenesis, underscoring a biosynthetic role of mitochondria in cellular anabolism.

DOI: https://doi.org/10.1016/j.molcel.2025.11.022