ABSTRACT
Mitochondrial-derived peptides significantly expand the coding potential of the human mitochondrial genome. Here, we report the discovery of MTALTCO1, a 259 amino-acid protein encoded by a mitochondrial alternative open reading frame found in the +3 reading frame of the cytochrome oxidase 1 gene (CO1). Using a custom antibody, we confirmed the mitochondrial expression of MTALTCO1 in human cell lines. Sequence analysis revealed high arginine content and an elevated isoelectric point that were not contingent on CO1’s amino acid sequence, suggesting selective pressures might be acting on this protein. MTALTCO1 displays extensive fusion-fission dynamics at the interspecies level, yet produces a full-length protein throughout human mitochondrial lineages. Our findings highlight the importance of identifying novel mitochondrial-derived peptides and proteins in expanding our understanding of the mitochondrial proteome.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
↵a Co-first authors
We've corrected some referencing mistakes, adjusted figures and supplementary files as well as updated the materials and methods section to correct some wetlab and bioinformatics analyses that were described in too little detail. The results and discussion section was adjusted to account for the update in the materials and methods section and some variants data was added in the updated version.
