Myosin light chain kinase (MLCK) plays a central role in regulating the actin-myosin interaction of smooth muscle. MLCK phosphorylates the light chain of myosin in the presence of Ca2+ and calmodulin (CaM) thereby activating myosin so that it can interact with actin.
What happens when myosin light chain kinase is inhibited?
In theory, by inhibiting MLCK activity, smooth muscle cell contraction and vasospasm could potentially be abolished, independent of the source of stimulation.
What is dephosphorylation of myosin light chain?
This dephosphorylation reaction occurs in smooth muscle tissue and initiates the relaxation process of the muscle cells. Thus, myosin phosphatase undoes the muscle contraction process initiated by myosin light-chain kinase. The enzyme is highly conserved and is found in all organisms’ smooth muscle tissue.
What happens when myosin light chain kinase is phosphorylated?
Myosin light chain kinase from smooth muscle has been shown to be phosphorylated by cyclic AMP-dependent protein kinase, which leads to a decrease in the affinity of the kinase for Ca2+ . calmodulin and, hence, a decrease in enzymatic activity.
What activates myosin light kinase?
MLCK is activated by calmodulin in response to an increase in intracellular calcium. It then goes on to phosphorylate regulatory myosin light chains at residues serine 19 and threonine 18 [2][3]. These phosphorylations enhance the ATPase activity of actin-activated myosin and so promotes myosin-driven contraction.
What does MLC phosphatase do?
Myosin light chain phosphatase (MLCP) is responsible for the dephosphorylation of the regulatory light chain (RLC) of the motor protein myosin-II, and so negatively regulates actomyosin-based contractility.
Where is myosin light chain kinase found?
MLCK localizes to the spindle midzone during late metaphase and is maximally activated through calcium/calmodulin binding as the cleavage furrows begins to ingress.
What is myosin regulatory light chain?
Myosin regulatory light chain 2, ventricular/cardiac muscle isoform (MLC-2) also known as the regulatory light chain of myosin (RLC) is a protein that in humans is encoded by the MYL2 gene. MLC-2v interacts with the neck/tail region of the muscle thick filament protein myosin to regulate myosin motility and function.
Where is troponin C found?
muscle
Troponin C, also known as TN-C or TnC, is a protein that resides in the troponin complex on actin thin filaments of striated muscle (cardiac, fast-twitch skeletal, or slow-twitch skeletal) and is responsible for binding calcium to activate muscle contraction.
Is calmodulin in skeletal muscle?
Concluding remarks Calmodulin plays a central role in the regulation by Ca 2§ of diverse biological processes, including muscle contraction. Three calmodulin-dependent enzymes have been recognized in skeletal muscle: phosphorylase kinase, myosin light chain kinase and an SR protein kinase.
Is myosin light chain kinase an enzyme?
Myosin light chain kinase (MLCK) is a Ca2+–CaM-dependent enzyme that phosphorylates MLC at Ser-19 or Ser-19/Thr-18 (Dudek and Garcia, 2001; Lazar and Garcia, 1999; Verin et al., 1998a,b; Wadgaonkar et al., 2003).
What is the antibody for myosin light chain 2?
Phospho-Myosin Light Chain 2 (Thr18/Ser19) Antibody detects endogenous levels of myosin light chain 2 (smooth muscle) only when dually phosphorylated at threonine 18 and serine 19. The antibody does not cross-react with the cardiac isoform of myosin light chain 2.
How are antibodies purified from myosin?
Antibodies are purified by protein A and peptide affinity chromatography. Myosin is composed of six polypeptide chains: two identical heavy chains and two pairs of light chains.
What is the reactivity of this phospho specific polyclonal antibody?
This phospho specific polyclonal antibody is specific for phosphorylated pS20 of human myosin light chain. Reactivity with non-phosphorylated human myosin light chain is less than 1% by ELISA.
How should I store myosin light chain 2 mountant?
For best results, allow mountant to cure overnight at room temperature. For long-term storage, store slides flat at 4°C protected from light. Phospho-Myosin Light Chain 2 (Ser19) Antibody detects endogenous levels of myosin light chain 2 (smooth muscle) only when phosphorylated at serine 19.
