Myosin binding protein-C: enigmatic regulator of cardiac contraction.
Myosin binding protein C (MyBPC) is a sarcomeric protein whose role in sarcomere structure and regulation of contraction is currently under investigation. It is a member of the immunoglobulin superfamily and is found in the C-zone of the A-band of the sarcomere. The elongated structure of MyBPC is composed of a series of immunoglobulin and fibronectin domains, with the C-terminal domains binding to the myosin thick filament and the N-terminal domains interacting with the myosin subfragment-2 (S2) neck region and possibly the actin thin filament. The functions of MyBPC are to stabilise the sarcomere structure and to regulate contraction. When phosphorylated near its N-terminus, MyBPC no longer binds myosin-S2, causing an increase in the ordering of the myosin heads, ATPase activity, F(max) and Ca(2+) sensitivity of contraction. Mutations in MyBPC have been found to cause familial hypertrophic cardiomyopathy (FHC) and changes in MyBPC phosphorylation have been linked to cardiac ischaemia-reperfusion injury.
Oakley
Cecily E
CE
Pathology Discipline, School of Medical Science and Bosch Institute, University of Sydney, NSW 2006, Australia.
Chamoun
Jean
J
Brown
Louise J
LJ
Hambly
Brett D
BD
D000818:Animals; D002312:Cardiomyopathy, Hypertrophic / Q000378:metabolism / Q000503:physiopathology; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D009200:Myocardial Contraction / Q000502:physiology*; D010766:Phosphorylation; D015427:Reperfusion Injury / Q000378:metabolism / Q000503:physiopathology; D012518:Sarcomeres / Q000502:physiology; D000099163:Myosin Binding Protein C
D002352:Carrier Proteins; D000099163:Myosin Binding Protein C