O-GlcNAc transferase (OGT) is an enzyme for the reversible post-translational modification of serine and threonine residues of proteins, including phospholamban, calmodulin kinase II, and troponin I. The hyperglycemia-induced hexosamine pathway supplies the N-acetylglucosamine moiety (O-GlcNAc), which is O-linked to these proteins by OGT. Here, OGT is linked to Hyperglycemia.