Myosin light chain interacting protein

Coiled-Coil Domains of the cGMP-Dependent Protein Kinase la and Its Interaction with the Myosin Binding Subunit of the Myosin Light Chains Phosphase , Protein Peptide Lett., 2011, 18, 966. 

The ETa receptor activates G proteins of the Gq/n and G12/i3 family. The ETB receptor stimulates G proteins of the G and Gq/11 family. In endothelial cells, activation of the ETB receptor stimulates the release of NO and prostacyclin (PGI2) via pertussis toxin-sensitive G proteins. In smooth muscle cells, the activation of ETA receptors leads to an increase of intracellular calcium via pertussis toxin-insensitive G proteins of the Gq/11 family and to an activation of Rho proteins most likely via G proteins of the Gi2/i3 family. Increase of intracellular calcium results in a calmodulin-dependent activation of the myosin light chain kinase (MLCK, Fig. 2). MLCK phosphorylates the 20 kDa myosin light chain (MLC-20), which then stimulates actin-myosin interaction of vascular smooth muscle cells resulting in vasoconstriction. Since activated Rho... 

Effect of protein-bound Ca TpC 4Ca antagonizes Tpl inhibition of F-actin-myosin interaction (allows F-actin activation of ATPase) Calmodulin 4Ca activates myosin light chain kinase that phosphorylates myosin p-light chain. The phosphorylated p-light chain no longer inhibits F-actin-myosin interaction (allows F-actin activation of ATPase). 

Many of the biochemical and molecular events that are responsible for uterine smooth muscle contraction are the same as those that control other smooth muscle tissues (Fig. 62.1). Once uterine smooth muscle sensitivity has been augmented, actin and myosin must interact for contraction to occur. This interaction depends on the phosphorylation of the contractile proteins by the enzyme myosin light chain kinase (MLCK). This enzyme requires Ca++ and is active only when associated with calmodulin. Activation of the entire muscle contraction... 

Cytoplasmic calcium concentration phosphorylation of myosin light chains and (less important) other proteins interactions with actin-binding proteins. 

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