Signaling Intermediate In Toll Pathway Evolutionarily Conserved Ortholog (SITPEC)

The longest, called variant 1, utilizes all 8 exons and encodes a deduced 431-amino acid protein with a calculated molecular mass of 50 kD. Western blot analysis of fractionated human embryonic kidney cells detected a protein of about 50 kD in the cytoplasm/nuclear fraction and a protein of about 45 kD in the mitochondrial fraction. The first 48 amino acids of ECSIT constitute a mitochondrial targeting signal.the 45-kD mitochondrial ECSIT protein, but not the 50-kD cytosolic protein, was a component of higher molecular mass complexes of about 500, 600, and 850 kD. ECSIT copurified with the mitochondrial complex I assembly chaperone NDUFAF1, and knockdown of ECSIT resulted in impaired complex I assembly and disturbed mitochondrial function.