|Detection of Mouse MyBPC3 by Western Blot. Western blot shows lysates of mouse embryonic heart tissue. PVDF membrane was probed with 2 µg/mL of Rat Anti-Mouse MyBPC3 Monoclonal Antibody (Catalog # MAB7199) followed by HRP-conjugated Anti-Rat IgG Secondary Antibody (Catalog # HAF005). A specific band was detected for MyBPC3 at approximately 140 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.|
MyBPC3 (Myosin-binding protein C-cardiac type) is a 140-150 kDa member of the MyBP family, Ig superfamily of proteins. It is expressed in cardiac muscle, and contributes both to myosin filament structure by interacting with light meromysin, and the regulation of contraction by binding to myosin subfragment-2, which results in a reduction of actomyosin ATPase activity. Mouse MyBPC3 is 1270 amino acids (aa) in length. It contains five consecutive C2-type Ig-like domains (aa 151-767), three FN type III repeats (aa 768-958), and two additional C-terminal Ig-like domains (aa 967-1270). There are at least three utilized phosphorylation sites and one Pro‑rich region (aa 100-150). In human, multiple mutations generate variable-length premature truncated forms of MyBPC3. There are two potential isoform variants. One basically shows a six aa substitution for aa 339-344, while a second contains the same six aa substitution coupled to an eight aa extension at the N-terminus. MyBPC3 is a thick filament-associated protein located in the crossbridge region of cardiac muscle sarcomeres. It is known to be a physiological substrate of cAMP‑dependent protein kinase. MyBPC3 has a role in sarcomeric structure and in the regulation of cardiac muscle contraction. MyBPC3 is released into the coronary effluent during myocardial infarction. Mutations in MYBPC3 are associated with hypertrophic cardiomyopathy. Within aa 2-169, mouse MyBPC3 shares 71% and 85% aa sequence identity with human and rat MyBPC3, respectively.