Ethylmalonic encephalopathy ETHE1 p. D165H mutation alters the mitochondrial function in human skeletal muscle proteome

•Mitochondrial proteins are differentially expressed in EE patient’s skeletal muscle.•Most of the proteins are down-regulated in the OXPHOS complex IV.•Altered proteins are involved predominantly in oxidoreductase activity. Ethylmalonic encephalopathy (EE) is a rare autosomal recessive inborn error of metabolism. To study the molecular effects of ETHE1 p. D165H mutation, we employed mass spectrometry-based mitochondrial proteome and phosphoproteome profiling in the human skeletal muscle. Eighty-six differentially altered proteins were identified, of which thirty-seven mitochondrial proteins were differentially expressed, and most of the proteins (37%) were down-regulated in the OXPHOS complex-IV. Also, nine phosphopeptides that correspond to eight mitochondrial proteins were significantly affected in EE patient. These altered proteins recognized are involved in several pathways and molecular functions, predominantly in oxidoreductase activity. This is the first study that has integrated proteome and phosphoproteome of skeletal muscle and identified multiple proteins associated in the pathogenesis of EE.