Structural Studies of Glycerinated Skeletal Muscle. I. A-Band Length and Cross-Bridge Period in ATP-Contracted Fibers

1984 ◽  
pp. 135-155 ◽  
Author(s):  
Paul Dreizen ◽  
Lawrence Herman ◽  
Jacob E. Berger
Keyword(s):  
Skeletal Muscle ◽  
Structural Studies ◽  
Cross Bridge

Cooperative attachment of cross bridges predicts regulation of smooth muscle force by myosin phosphorylation

2004 ◽  
Vol 287 (3) ◽  
pp. C594-C602 ◽  
Author(s):  
Christopher M. Rembold ◽  
Robert L. Wardle ◽  
Christopher J. Wingard ◽  
Timothy W. Batts ◽  
Elaine F. Etter ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Time Course ◽  
Muscle Force ◽  
Regulatory System ◽  
Force Development ◽  
Cross Bridge ◽  
Cross Bridges ◽  
The Relationship ◽  
Cooperative Activation

Serine 19 phosphorylation of the myosin regulatory light chain (MRLC) appears to be the primary determinant of smooth muscle force development. The relationship between MRLC phosphorylation and force is nonlinear, showing that phosphorylation is not a simple switch regulating the number of cycling cross bridges. We reexamined the MRLC phosphorylation-force relationship in slow, tonic swine carotid media; fast, phasic rabbit urinary bladder detrusor; and very fast, tonic rat anococcygeus. We found a sigmoidal dependence of force on MRLC phosphorylation in all three tissues with a threshold for force development of ∼0.15 mol Pi/mol MRLC. This behavior suggests that force is regulated in a highly cooperative manner. We then determined whether a model that employs both the latch-bridge hypothesis and cooperative activation could reproduce the relationship between Ser19-MRLC phosphorylation and force without the need for a second regulatory system. We based this model on skeletal muscle in which attached cross bridges cooperatively activate thin filaments to facilitate cross-bridge attachment. We found that such a model describes both the steady-state and time-course relationship between Ser19-MRLC phosphorylation and force. The model required both cooperative activation and latch-bridge formation to predict force. The best fit of the model occurred when binding of a cross bridge cooperatively activated seven myosin binding sites on the thin filament. This result suggests cooperative mechanisms analogous to skeletal muscle that will require testing.

scholarly journals The Regulatory Light Chains of Myosin Modulate Cross-bridge Cycling in Skeletal Muscle

1996 ◽  
Vol 271 (9) ◽  
pp. 5246-5250 ◽  
Author(s):  
Danuta Szczesna ◽  
Jiaju Zhao ◽  
James D. Potter
Keyword(s):  
Skeletal Muscle ◽  
Light Chains ◽  
Regulatory Light Chains ◽  
Cross Bridge ◽  
Light Chains Of Myosin

scholarly journals Ca2+ Regulation of Rabbit Skeletal Muscle Thin Filament Sliding: Role of Cross-Bridge Number

2003 ◽  
Vol 85 (3) ◽  
pp. 1775-1786 ◽  
Author(s):  
Bo Liang ◽  
Ying Chen ◽  
Chien-Kao Wang ◽  
Zhaoxiong Luo ◽  
Michael Regnier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Thin Filament ◽  
Rabbit Skeletal Muscle ◽  
Cross Bridge ◽  
Muscle Thin Filament ◽  
Bridge Number

scholarly journals Dependence of cross-bridge kinetics on myosin light chain isoforms in rabbit and rat skeletal muscle fibres

2006 ◽  
Vol 571 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Oleg Andruchov ◽  
Olena Andruchova ◽  
Yishu Wang ◽  
Stefan Galler
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Fibres ◽  
Rat Skeletal Muscle ◽  
Cross Bridge ◽  
Skeletal Muscle Fibres

Light-chain phosphorylation and cross-bridge conformation in myosin from vertebrate skeletal muscle

Biochemistry ◽  
1983 ◽  
Vol 22 (3) ◽  
pp. 525-530 ◽  
Author(s):  
Ana Mrakovcic-Zenic ◽  
Emil Reisler
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Cross Bridge ◽  
Vertebrate Skeletal Muscle
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