A cooperative organelle biogenesis program in mammalian cells

The compartmentalisation of distinct organelles within eukaryotic cells is essential for their diverse functions, however, how their structures and functions depend on each other has not been systematically explored. We combined a fluorescent reporter of mitochondrial stress with genome-wide CRISPR knockout screening and identified networks of genes involved in the biogenesis and metabolism of diverse organelles. Targeted organelle gene knockouts identified that defects in peroxisomes, Golgi, and ER cause mitochondrial fragmentation and dysfunction. Correlative light and electron microscopy analysed using artificial intelligence-directed voxel extraction revealed in unprecedented detail how impaired mitochondrial interactions with diverse organelles caused cell-wide defects in their morphology and biogenesis. Multi-omics analyses identified a unified proteome stress response and global shifts in lipid and glycoprotein homeostasis that are elicited when organelle biogenesis is compromised. Our comprehensive resource has defined metabolic and morphological interactions between organelles that can be mined to understand how changes in organelle components drive diverse cellular pathologies. RNA-Seq performed on PEX26, GOLGA5, SEC61A2, GOLGA8M and SEC61 knockouts and wild type mice, in triplicate.