Facioscapulohumeral muscular dystrophy is associated with altered myoblast proteome dynamics

Proteomic studies in facioscapulohumeral muscular dystrophy (FSHD) could offer new insight to disease mechanisms underpinned by post-transcriptional processes. We used stable isotope (deuterium oxide; D2O) labelling and peptide mass spectrometry to investigate the abundance and turnover rates of proteins in cultured muscle cells from 2 individuals affected by FSHD and their unaffected siblings (UASb). We measured the abundance of 4485 proteins and the turnover rate of 2324 proteins in each (n = 4) myoblast sample. FSHD myoblasts exhibited a greater abundance but slower turnover rate of subunits of mitochondrial respiratory complexes and mitochondrial ribosomal proteins, which may indicate an accumulation of older less viable mitochondrial proteins in myoblasts from individuals affected by FSHD. Our results highlight the importance of post-transcriptional processes and protein turnover in FSHD pathology and provide a resource for the FSHD research community to explore this burgeoning aspect of FSHD. ### Competing Interest Statement The authors have declared no competing interest.