Cross-Bridge Movement and the Conformational State of the Myosin Hinge in Skeletal Muscle

1982 ◽  
pp. 173-175
Author(s):  
Hitoshi Ueno ◽  
William F. Harrington
1981 ◽  
Vol 149 (4) ◽  
pp. 619-640 ◽  
Author(s):  
Hitoshi Ueno ◽  
William F. Harrington

2004 ◽  
Vol 287 (3) ◽  
pp. C594-C602 ◽  
Author(s):  
Christopher M. Rembold ◽  
Robert L. Wardle ◽  
Christopher J. Wingard ◽  
Timothy W. Batts ◽  
Elaine F. Etter ◽  
...  

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.


1996 ◽  
Vol 271 (9) ◽  
pp. 5246-5250 ◽  
Author(s):  
Danuta Szczesna ◽  
Jiaju Zhao ◽  
James D. Potter

2003 ◽  
Vol 85 (3) ◽  
pp. 1775-1786 ◽  
Author(s):  
Bo Liang ◽  
Ying Chen ◽  
Chien-Kao Wang ◽  
Zhaoxiong Luo ◽  
Michael Regnier ◽  
...  

2006 ◽  
Vol 571 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Oleg Andruchov ◽  
Olena Andruchova ◽  
Yishu Wang ◽  
Stefan Galler

Biochemistry ◽  
1983 ◽  
Vol 22 (3) ◽  
pp. 525-530 ◽  
Author(s):  
Ana Mrakovcic-Zenic ◽  
Emil Reisler

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