The frataxin (FXN) protein exists in different forms, precursor, intermediate and mature. The mature form is what is imported to the mitochondria and considered the functional form of the protein. This study finds that regulation of FXN protein levels is complex and that total amounts can be modulated chemically and genetically without altering the absolute amount of mature FXN protein.
Read more here: http://www.ncbi.nlm.nih.gov/pubmed/26671574
