A genetic program boosts mitochondrial function to power macrophage tissue invasion (RNA-seq/Polysome-seq, S2 cells)

Metabolic adaptation to changing demands underlies homeostasis. During inflammation or metastasis, cells leading migration into challenging environments require an energy boost, however what controls this capacity is unknown. We identify a previously unstudied nuclear protein, Atossa, as changing metabolism in Drosophila melanogaster immune cells to promote tissue invasion. Atossa's vertebrate orthologs, FAM214A-B can fully substitute for Atossa, indicating functional conservation from flies to mammals. Atossa increases mRNA levels of Porthos, an unstudied RNA helicase and two metabolic enzymes, LKR/SDH and GR/HPR. Porthos increases translation of a gene subset, including those affecting mitochondrial functions, the electron transport chain, and metabolism. Respiration measurements and metabolomics indicate that Atossa and Porthos power up mitochondrial oxidative phosphorylation to produce sufficient energy for pioneer macrophages to forge a path into tissues. As increasing oxidative phosphorylation enables many crucial physiological responses, this unique genetic program may modulate a wide range of cellular behaviors beyond migration. Input and Polysome mRNA content from Control, GFP dsRNA treated S2 cells and Porthos (CG9253) dsRNA