Myosin light chain kinases

  title={Myosin light chain kinases},
  author={Patricia J. Gallagher and B. PAUL HERRING and James T Stull},
  journal={Journal of Muscle Research \& Cell Motility},
A remarkable variety of extracellular signalling molecules effect signal transduction by receptormediated increases in cytosolic Ca2‡ concentration. This Ca2‡ response is a central event for the regulation or modulation of many cell processes, including those dependent upon actin-activation of the myosin II motor protein. In the case of striated muscles, Ca2‡ binds to the thin filament regulatory protein troponin allowing actin to activate sarcomeric myosin MgATPase, bringing about muscle… 

Regulation of smooth muscle contraction by calcium, monomeric GTPases of the Rho subfamily and their effector kinases.

Whether Ca2+ is required for tension maintenance of an agonist induced contraction using the membrane permeant form of the caged Ca-chelator, diazo2, is tested.

Regulation of Myosin Light Chain Phosphorylation

The varied activities of these major signaling pathways endow SMCs with different contractile profiles such as phasic and tonic contractions to meet the diversified physiological requirements.

Increasing evidence of mechanical force as a functional regulator in smooth muscle myosin light chain kinase

A CaM-independent activation mechanism for smMLCK by mechanical release of the inhibitory elements is investigated via high throughput AFM single-molecule force spectroscopy, indicating restored substrate-binding capability due to mechanically induced removal of the auto-inhibitory regulatory region.

Ca2+ sensitivity of smooth muscle and nonmuscle myosin II: modulated by G proteins, kinases, and myosin phosphatase.

It is suggested that the RhoA/ROK pathway is constitutively active in a number of organs under physiological conditions; its aberrations play major roles in several disease states, particularly impacting on Ca2+ sensitization of smooth muscle in hypertension and possibly asthma and on cancer neoangiogenesis and cancer progression.

Smooth Muscle Myosin Phosphatase-associated Kinase Induces Ca2+ Sensitization via Myosin Phosphatase Inhibition*

Using an antibody that specifically recognizes MYPT1 phosphorylated at Thr654(M130 numbering), it is determined that this calcium-independent contraction in β-escin-permeabilized rabbit ileal smooth muscle was correlated with an increase in MYPT 1 phosphorylation.

Biochemistry of smooth muscle myosin light chain kinase.

Regulation of myosin light chain kinase and telokin expression in smooth muscle tissues.

Some of the recent studies that have described the transcriptional regulation of mylk1 gene products in smooth muscle tissues are highlighted and the implications of these findings for regulation of expression of other smooth muscle-specific genes are discussed.

Calponin (CaP) as a latch-bridge protein — a new concept in regulation of contractility in smooth muscles

  • P. Szymanski
  • Biology
    Journal of Muscle Research & Cell Motility
  • 2004
It is proposed that CaP tethers thin and thick filaments and this CaP effect is exerted when its central part binds to F-actin, whereas the NH2-terminal half simultaneously interacts with phosphorylated MRLC.

Vectorial phosphorylation of filamentous smooth muscle myosin by calmodulin and myosin light chain kinase complex

  • A. Sobieszek
  • Biology, Chemistry
    Journal of Muscle Research & Cell Motility
  • 2004
Phosphorylation progress curves obtained from mixtures of the native-like, and CaM- and MLCK-free filaments indicated that the CaM/MLCK complex preferentially phosphorylation its parent filaments and, as result, the whole myosin present was not maximally phosphorylated.



Phosphorylation of myosin light chain kinase: a cellular mechanism for Ca2+ desensitization

Results from experiments designed to satisfy the criteria of Krebs and Beavo for establishing the physiological significance of enzyme phosphorylation have provided insights into the cellular regulation and function of this phosphorylated myosin light chain kinase in smooth muscle.

Regulation of smooth muscle contractile elements by second messengers.

The purposes of the present chapter are to discuss Ca2+ -dependent mechanisms other than myosin light chain phosphorylation by which contractile force in smooth muscle may be reg­ ulated, and other second messenger mechanisms that regulate contractile elements or the myOSin kinase/phosphatase system.

Myosin light chain kinase phosphorylation in tracheal smooth muscle.

The role of myosin light chain kinase phosphorylation in beta-adrenergic relaxation of tracheal smooth muscle.

Findings are inconsistent with a role of myosin light chain kinase phosphorylation in mediating relaxation of tracheal smooth muscle by beta-adrenergic agonists, as cyclic AMP-dependent effects on cytoplasmic calcium concentrations may be more important in mediates relaxation.

Phosphorylation of myosin light chain kinase by the multifunctional calmodulin-dependent protein kinase II in smooth muscle cells.

Myosin light chain phosphorylation in vertebrate striated muscle: regulation and function.

In skinned fibers, RLC phosphorylation increases force production at low levels of Ca2+ activation, via a leftward shift of the force-pCa relationship, and increases the rate of force development over a wide range of activation levels.

Myosin light chain kinase-regulated endothelial cell contraction: the relationship between isometric tension, actin polymerization, and myosin phosphorylation

The effects of thrombin stimulation on human umbilical vein endothelial cell (HUVE) actin, myosin II and the functional correlate of the activated actomyosin based contractile system, isometric tension development are reported.

Phosphorylation of myosin regulatory light chains by the molluscan twitchin kinase.

Data reveal the first potential substrate for any of the giant protein kinases and support a dual role of twitchin in molluscan muscle as a cytoskeletal protein as well as a myosin light chain kinase.