Ca2+ activation of smooth muscle contraction: evidence for the involvement of calmodulin that is bound to the triton insoluble fraction even in the absence of Ca2+.

@article{Wilson2002Ca2AO,
  title={Ca2+ activation of smooth muscle contraction: evidence for the involvement of calmodulin that is bound to the triton insoluble fraction even in the absence of Ca2+.},
  author={David Peter Wilson and Cindy Sutherland and M. P. Walsh},
  journal={The Journal of biological chemistry},
  year={2002},
  volume={277 3},
  pages={2186-92}
}
Smooth muscle contraction is activated by phosphorylation of the 20-kDa light chains of myosin catalyzed by Ca(2+)/calmodulin (CaM)-dependent myosin light chain kinase (MLCK). According to popular current theory, the CaM involved in MLCK regulation is Ca(2+)-free and dissociated from the kinase at resting cytosolic free Ca(2+) concentration ([Ca(2+)](i)). An increase in [Ca(2+)](i) saturates the four Ca(2+)-binding sites of CaM, which then binds to and activates actin-bound MLCK. The results of… CONTINUE READING