In addition, yeast Pmt4 provides a powerful model for understanding the significant group of congenital muscular dystrophies linked to reduced O-mannosylation of α-dystroglycan (αDG) by POMT1-POMT2, as it mannosylates αDG-derived peptides and is catalytically impaired by the insertion of pathogenic POMT1 mutations18. Here, POMT1 is linked to muscular dystrophy.