Distribution of known post-translational modifications across cMyBP-C . (A) Illustration demonstrating how cMyBP-C incorporates with myosin and actin, modulated by phosphorylation of the regulatory motif (M). (B) Visualization of the individual domains of cMyBP-C, highlighting where specific post-translational modifications occur across the protein. S-glutathionylation of cMyBP-C has been shown to reduce rates of crossbridge cycling and increase passive tension in permeabilized heart preparations. Elevated levels of cMyBP-C S-glutathionylation are found in hypertrophic cardiomyopathy (HCM) and heart failure (HF), whereas phosphorylation of cMyBP-C tends to be reduced under the same conditions, suggesting a potential for cross talk between these two modifications. Acetylation and S-nitrosylation alter sarcomere function, but it remains to be determined if these modifications of cMyBP-C are specifically responsible for altered heart function. Individual PTM sites have been discovered for oxidation, O-GlcNAcylation, ubiquitination, but with unknown functional consequences. Global cMyBP-C citrullination and carbonylation have been confirmed, but with unknown functional effects. ? demonstrates where uncertainty in the literature exists. Figure made using BioRender.