APC/Cy7 Linked Polyclonal Antibody to Myosin Heavy Chain 7, Cardiac Muscle, Beta (MYH7)

Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing early-onset distal myopathy. [provided by RefSeq, Jul 2008]

MYH7: Muscle contraction. Defects in MYH7 are the cause of familial hypertrophic cardiomyopathy type 1 (CMH1). Familial hypertrophic cardiomyopathy is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death. Defects in MYH7 are the cause of myopathy myosin storage (MYOMS). In this disorder, muscle biopsy shows type 1 fiber predominance and increased interstitial fat and connective tissue. Inclusion bodies consisting of the beta cardiac myosin heavy chain are present in the majority of type 1 fibers, but not in type 2 fibers. Defects in MYH7 are the cause of scapuloperoneal myopathy MYH7-related (SPMM); also known as scapuloperoneal syndrome myopathic type. SPMM is a progressive muscular atrophia beginning in the lower legs and affecting the shoulder region earlier and more severely than distal arm. Defects in MYH7 are a cause of cardiomyopathy dilated type 1S (CMD1S). Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death. Defects in MYH7 are the cause of myopathy distal type 1 (MPD1). MPD1 is a muscular disorder characterized by early-onset selective weakness of the great toe and ankle dorsiflexors, followed by weakness of the finger extensors. Mild proximal weakness occasionally develops years later after the onset of the disease.

Protein type: Motor; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 14q12

Cellular Component: nucleoplasm; sarcomere; focal adhesion; cytoplasm; stress fiber; muscle myosin complex; Z disc; myosin complex

Molecular Function: calmodulin binding; microfilament motor activity; protein binding; ATPase activity; actin-dependent ATPase activity; actin binding; ATP binding

Biological Process: adult heart development; striated muscle contraction; muscle contraction; regulation of heart rate; metabolic process; ventricular cardiac muscle morphogenesis; regulation of the force of heart contraction; muscle filament sliding

Disease: Myopathy, Distal, 1; Scapuloperoneal Myopathy, Myh7-related; Myopathy, Myosin Storage; Cardiomyopathy, Dilated, 1s; Myopathy, Congenital, With Fiber-type Disproportion; Cardiomyopathy, Familial Hypertrophic, 1; Myopathy, Myosin Storage, Autosomal Recessive