Mutations in either the essential or regulatory light chains of myosin are associated with a rare myopathy in human heart and skeletal muscle

1996 ◽  
Vol 13 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Karl Poetter ◽  
He Jiang ◽  
Shahin Hassanzadeh ◽  
Stephen R. Master ◽  
Anthony Chang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Heart ◽  
Light Chains ◽  
Regulatory Light Chains ◽  
Light Chains Of Myosin

scholarly journals Regulatory Light Chains Fine-Tune Skeletal Muscle Myosin-II Function

2021 ◽  
Vol 120 (3) ◽  
pp. 344a
Author(s):  
Arnab Nayak ◽  
Tianbang Wang ◽  
Peter Franz ◽  
Walter Steffen ◽  
Igor Chizhov ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myosin Ii ◽  
Light Chains ◽  
Skeletal Muscle Myosin ◽  
Regulatory Light Chains ◽  
Muscle Myosin ◽  
Fine Tune

scholarly journals Regulatory and Essential Light Chains of Myosin Rotate Equally during Contraction of Skeletal Muscle

2002 ◽  
Vol 82 (6) ◽  
pp. 3150-3159 ◽  
Author(s):  
Julian Borejdo ◽  
Dmitry S. Ushakov ◽  
Irina Akopova
Keyword(s):  
Skeletal Muscle ◽  
Light Chains ◽  
Light Chains Of Myosin

scholarly journals Structural changes accompanying phosphorylation of tarantula muscle myosin filaments.

1987 ◽  
Vol 105 (3) ◽  
pp. 1319-1327 ◽  
Author(s):  
R Craig ◽  
R Padrón ◽  
J Kendrick-Jones
Keyword(s):  
Gel Electrophoresis ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Structural Changes ◽  
Striated Muscle ◽  
Light Chains ◽  
Regulatory Light Chains ◽  
Myosin Filaments ◽  
Muscle Myosin ◽  
Light Chains Of Myosin

Electron microscopy has been used to study the structural changes that occur in the myosin filaments of tarantula striated muscle when they are phosphorylated. Myosin filaments in muscle homogenates maintained in relaxing conditions (ATP, EGTA) are found to have nonphosphorylated regulatory light chains as shown by urea/glycerol gel electrophoresis and [32P]phosphate autoradiography. Negative staining reveals an ordered, helical arrangement of crossbridges in these filaments, in which the heads from axially neighboring myosin molecules appear to interact with each other. When the free Ca2+ concentration in a homogenate is raised to 10(-4) M, or when a Ca2+-insensitive myosin light chain kinase is added at low Ca2+ (10(-8) M), the regulatory light chains of myosin become rapidly phosphorylated. Phosphorylation is accompanied by potentiation of the actin activation of the myosin Mg-ATPase activity and by loss of order of the helical crossbridge arrangement characteristic of the relaxed filament. We suggest that in the relaxed state, when the regulatory light chains are not phosphorylated, the myosin heads are held down on the filament backbone by head-head interactions or by interactions of the heads with the filament backbone. Phosphorylation of the light chains may alter these interactions so that the crossbridges become more loosely associated with the filament backbone giving rise to the observed changes and facilitating crossbridge interaction with actin.

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