Phosphorylation of the regulatory light chains of myosin affects Ca2+ sensitivity of skeletal muscle contraction.

@article{Szczesna2002PhosphorylationOT,
  title={Phosphorylation of the regulatory light chains of myosin affects Ca2+ sensitivity of skeletal muscle contraction.},
  author={Danuta Szczesna and Jiaju Zhao and Michelle A Jones and Gang Zhi and James T Stull and James D. Potter},
  journal={Journal of applied physiology},
  year={2002},
  volume={92 4},
  pages={
          1661-70
        }
}
The role of phosphorylation of the myosin regulatory light chains (RLC) is well established in smooth muscle contraction, but in striated (skeletal and cardiac) muscle its role is still controversial. We have studied the effects of RLC phosphorylation in reconstituted myosin and in skinned skeletal muscle fibers where Ca2+ sensitivity and the kinetics of steady-state force development were measured. Skeletal muscle myosin reconstituted with phosphorylated RLC produced a much higher Ca2… 
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The molecular effects of skeletal muscle myosin regulatory light chain phosphorylation.
TLDR
It is shown that, independently of the thick filament backbone, the velocity of skeletal muscle myosin is decreased upon phosphorylation due to an increase in the myOSin duty cycle, consistent with the notion that strain slows the rate of ADP release in striated muscle.
Effects of myosin light chain phosphorylation on length-dependent myosin kinetics in skinned rat myocardium.
Regulatory light chains of striated muscle myosin. Structure, function and malfunction.
  • D. Szczesna
  • Biology
    Current drug targets. Cardiovascular & haematological disorders
  • 2003
TLDR
It is demonstrated that phosphorylation and Ca(2+) binding to the RLC play an important modulatory role in striated muscle contraction and that the ventricular isoform of human cardiac RLC has been shown to be one of the sarcomeric proteins associated with familial hypertrophic cardiomyopathy (FHC), an autosomal dominant disease characterized by left ventricular hypertrophy, myofibrillar disarray and sudden cardiac death.
Basal myosin light chain phosphorylation is a determinant of Ca2+ sensitivity of force and activation dependence of the kinetics of myocardial force development.
TLDR
The results suggest that basal phosphorylation of RLC plays a role in setting the kinetics of force development and Ca2+ sensitivity of force in cardiac muscle and argue that changes in RLC phosphorylated in the range examined here influence actin-myosin interaction kinetics differently in heart muscle than was previously reported for skeletal muscle.
Acceleration of Stretch Activation in Murine Myocardium due to Phosphorylation of Myosin Regulatory Light Chain
TLDR
RLC phosphorylation increases force and the rate of cross-bridge recruitment in murine myocardium, which would increase power generation in vivo and thereby enhance systolic function.
Cardiac Myosin Light Chain Kinase Is Necessary for Myosin Regulatory Light Chain Phosphorylation and Cardiac Performance in Vivo*
TLDR
Cardiac performance measured as fractional shortening decreased proportionally with decreased cMLCK expression culminating in heart failure in the setting of no RLC phosphorylation, appearing to be the predominant protein kinase that maintains basal RLCosphorylation that is required for normal physiological cardiac performance in vivo.
Phosphorylation of myosin regulatory light chain has minimal effect on kinetics and distribution of orientations of cross bridges of rabbit skeletal muscle.
TLDR
The effect of phosphorylation on skeletal cross-bridge kinetics and the distribution of orientations during steady-state contraction of rabbit muscle is investigated here and it is concluded that the state ofosphorylation of RLC had no effect on the rate of dissociation of cross bridges from thin filaments, on the rates of myosin head binding to thinfilaments, and on the level of power stroke.
Regulatory light chains modulate in vitro actin motility driven by skeletal heavy meromyosin.
The role of myosin regulatory light chain phosphorylation in cardiac health and disease
TLDR
It is proved that RLC phosphorylation level alteration impacts systolic myocardial performance in human health and disease by altering both myosin mechanics and kinetics.
The effect of myosin RLC phosphorylation in normal and cardiomyopathic mouse hearts
TLDR
The results support the notion that RLC phosphorylation works as a rescue mechanism alleviating detrimental functional effects of a disease causing mutation and decrease in maximal tension in Tg‐D166V–skinned muscle fibres.
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TLDR
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