NF-kappaB and JNK pathways mediate metabolic adaptation upon ESCRT-I deficiency
Endosomal Sorting Complexes Required for Transport (ESCRTs) are crucial for delivering membrane receptors or intracellular organelles for lysosomal degradation. Yet, how ESCRT dysfunction affects cell metabolism remained elusive. To address this, we analyzed transcriptomes of cells lacking TSG101 or VPS28 proteins, components of ESCRT-I subcomplex. ESCRT-I deficiency reduced the expression of genes encoding enzymes involved in oxidation of fatty acids and amino acids, and increased the expression of genes encoding glycolytic enzymes. Although depletion of ESCRT-I components did not impair mitochondrial biogenesis and ATP-linked respiration it caused intracellular accumulation of lipids and increased lactate production, hallmarks of aerobic glycolysis. Mechanistically, the observed transcriptional reprogramming towards glycolysis in the absence of ESCRT-I occurred due to activation of the canonical NF{kappa}B and JNK signaling pathways. Moreover, inhibiting lysosomal activity phenocopied the altered expression of metabolic genes and lipid homeostasis observed for ESCRT-I deficiency, indicating that ESCRT-I restricts glycolysis by mediating lysosomal degradation.