Axial distribution of myosin binding protein-C is unaffected by mutations in human cardiac and skeletal muscle

作者：Vydyanath Anupama^*; Gurnett Christina A; Marston Steve; Luther Pradeep K

来源：Journal of Muscle Research and Cell Motility, 2012, 33(1): 61-74.

DOI：10.1007/s10974-012-9286-9

• Hypertrophic cardiomyopathy
• Distal arthrogryposis type 1
• C-protein
• MyBP-C
• Myosin binding protein-C mutations
• Thick filament

Myosin binding protein-C (MyBP-C), a major thick filament associated sarcomeric protein, plays an important functional and structural role in regulating sarcomere assembly and crossbridge formation. Missing or aberrant MyBP-C proteins (both cardiac and skeletal) have been shown to cause both cardiac and skeletal myopathies, thereby emphasising its importance for the normal functioning of the sarcomere. Mutations in cardiac MyBP-C are a major cause of hypertrophic cardiomyopathy (HCM), while mutations in skeletal MyBP-C have been implicated in a disease of skeletal muscle-distal arthrogryposis type 1 (DA-1). Here we report the first detailed electron microscopy studies on human cardiac and skeletal tissues carrying MyBP-C gene mutations, using samples obtained from HCM and DA-1 patients. We have used established image averaging methods to identify and study the axial distribution of MyBP-C on the thick filament by averaging profile plots of the A-band of the sarcomere from electron micrographs of human cardiac and skeletal myopathy specimens. Due to the difficulty of obtaining normal human tissue, we compared the distribution to the A-band structure in normal frog skeletal, rat cardiac muscle and in cardiac muscle of MyBP-C-deficient mice. Very similar overall profile averages were obtained from the C-zones in cardiac HCM samples and skeletal DA-1 samples with MyBP-C gene mutations, suggesting that mutations in MyBP-C do not alter its mean axial distribution along the thick filament.

• 出版日期2012-5