scholarly journals MiRNA-155 targets myosin light chain kinase and modulates actin cytoskeleton organization in endothelial cells

2014 ◽  
Vol 306 (8) ◽  
pp. H1192-H1203 ◽  
Author(s):  
Martina Weber ◽  
Sinae Kim ◽  
Nicole Patterson ◽  
Kimberly Rooney ◽  
Charles D. Searles
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Actin Cytoskeleton ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Cytoskeleton Organization ◽  
Actin Cytoskeleton Organization ◽  
Mouse Aorta

Previously, we identified a microRNA (miRNA) signature for endothelial cells (ECs) subjected to unidirectional shear stress (USS). MiR-155, a multifunctional miRNA that has been implicated in atherosclerosis, was among the shear stress-responsive miRNAs. Here, we examined the role of miR-155 in modulating EC phenotype and function. In vitro, increased miR-155 levels in human ECs induced changes in morphology and filamentous (F)-actin organization. In addition, ECs transfected with miR-155 mimic were less migratory and less proliferative and had less apoptosis compared with control ECs. In mouse aorta, miR-155 expression was increased in the intima of thoracic aorta, where blood flow produces steady and unidirectional shear stress, compared with the intima of the lower curvature of the aortic arch, which is associated with oscillatory and low shear stress. These differences in miR-155 expression were associated with distinct changes in EC morphology and F-actin. The effects of miR-155 in vitro were mediated through suppression of two key regulators of the EC cytoskeleton organization: RhoA and myosin light chain kinase (MYLK). A novel direct interaction between miR-155 and the MYLK 3′UTR was verified by luciferase-MYLK 3′UTR reporter assays. Furthermore, the intensity of immunofluorescence staining for RhoA and MYLK in mouse aorta correlated inversely with miR-155 expression. In conclusion, a prominent effect of the multifunctional miR-155 in ECs is modulation of phenotype through alterations in RhoA, MYLK expression, and actin cytoskeleton organization.

The Regulation of Myosin Light Chain Kinase by Ca++ and Calmodulin in Vitro and in Vivo

1982 ◽  
pp. 219-238 ◽  
Author(s):  
J. T. Stull ◽  
D. K. Blumenthal ◽  
B. R. Botterman ◽  
G. A. Klug ◽  
D. R. Manning ◽  
...  
Keyword(s):  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain

Is phosphorylation the main physiological action of myosin light chain kinase?

1994 ◽  
Vol 72 (11) ◽  
pp. 1377-1379 ◽  
Author(s):  
Setsuro Ebashi ◽  
Hideto Kuwayama
Keyword(s):  
Amino Acid ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Actin Binding ◽  
In Vitro System ◽  
Beryllium Sulfate ◽  
Kinase Phosphorylation ◽  
Actin Binding Site

The 155-kDa component of bovine stomach, which exhibits a strong actomyosin (AM) activating activity and a relatively weak myosin light chain kinase (MLCK) activity, has a strong affinity for the actin filament and the actin-binding site is confined to an 80 amino acid residue on its N-terminal side. This affinity may play a crucial role in AM activation. Some reagents preferentially abolish either the AM-activating effect or MLCK activity. In conclusion, MLCK of the 155-kDa component does not play a fundamental role in activating the AM system as far as the in vitro system is concerned. The possible mechanism of AM activation by the component is discussed.Key words: myosin light chain kinase, phosphorylation of myosin light chain, leiotonin, wortmannin, beryllium sulfate.

scholarly journals The Fibrinogen Globe of Tenascin-C Promotes Basic Fibroblast Growth Factor-induced Endothelial Cell Elongation

1999 ◽  
Vol 10 (9) ◽  
pp. 2933-2943 ◽  
Author(s):  
Susanne Schenk ◽  
Ruth Chiquet-Ehrismann ◽  
Edouard J. Battegay
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Fibroblast Growth ◽  
Aortic Endothelial Cells ◽  
Tenascin C ◽  
Cytoskeleton Organization ◽  
Actin Cytoskeleton Organization

To investigate the potential role of tenascin-C (TN-C) on endothelial sprouting we used bovine aortic endothelial cells (BAECs) as an in vitro model of angiogenesis. We found that TN-C is specifically expressed by sprouting and cord-forming BAECs but not by nonsprouting BAECs. To test whether TN-C alone or in combination with basic fibroblast growth factor (bFGF) can enhance endothelial sprouting or cord formation, we used BAECs that normally do not sprout and, fittingly, do not express TN-C. In the presence of bFGF, exogenous TN-C but not fibronectin induced an elongated phenotype in nonsprouting BAECs. This phenotype was due to altered actin cytoskeleton organization. The fibrinogen globe of the TN-C molecule was the active domain promoting the elongated phenotype in response to bFGF. Furthermore, we found that the fibrinogen globe was responsible for reduced cell adhesion of BAECs on TN-C substrates. We conclude that bFGF-stimulated endothelial cells can be switched to a sprouting phenotype by the decreased adhesive strength of TN-C, mediated by the fibrinogen globe.

Lanthanum chloride causes blood–brain barrier disruption through intracellular calcium-mediated RhoA/Rho kinase signaling and myosin light chain kinase

Metallomics ◽  
2020 ◽  
Author(s):  
Jie Wu ◽  
Jinghua Yang ◽  
Miao Yu ◽  
Wenchang Sun ◽  
Yarao Han ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Intracellular Calcium ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Rho Kinase ◽  
Endothelial Barrier ◽  
Blood Brain Barrier Disruption ◽  
Intracellular Ca ◽  
Brain Barrier Disruption

Lanthanum caused endothelial barrier hyperpermeability, loss of VE-cadherin and rearrangement of the actin cytoskeleton, though intracellular Ca2+-mediated RhoA/ROCK and MLCK pathways.

scholarly journals Myosin light chain kinase and myosin light chain phosphatase from Dictyostelium: effects of reversible phosphorylation on myosin structure and function.

1987 ◽  
Vol 104 (5) ◽  
pp. 1309-1323 ◽  
Author(s):  
L M Griffith ◽  
S M Downs ◽  
J A Spudich
Keyword(s):  
Enzyme Activity ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Tight Binding ◽  
Subsequent Treatment ◽  
Myosin Light Chain Phosphatase ◽  
In Vitro Motility Assay ◽  
Dictyostelium Myosin

We have partially purified myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) from Dictyostelium discoideum. MLCK was purified 4,700-fold with a yield of approximately 1 mg from 350 g of cells. The enzyme is very acidic as suggested by its tight binding to DEAE. Dictyostelium MLCK has an apparent native molecular mass on HPLC G3000SW of approximately 30,000 D. Mg2+ is required for enzyme activity. Ca2+ inhibits activity and this inhibition is not relieved by calmodulin. cAMP or cGMP have no effect on enzyme activity. Dictyostelium MLCK is very specific for the 18,000-D light chain of Dictyostelium myosin and does not phosphorylate the light chain of several other myosins tested. Myosin purified from log-phase amebas of Dictyostelium has approximately 0.3 mol Pi/mol 18,000-D light chain as assayed by glycerol-urea gel electrophoresis. Dictyostelium MLCK can phosphorylate this myosin to a stoichiometry approaching 1 mol Pi/mol 18,000-D light chain. MLCP, which was partially purified, selectively removes phosphate from the 18,000-D light chain but not from the heavy chain of Dictyostelium myosin. Phosphatase-treated Dictyostelium myosin has less than or equal to 0.01 mol Pi/mol 18,000-D light chain. Phosphatase-treated myosin could be rephosphorylated to greater than or equal to 0.96 mol Pi/mol 18,000-D light chain by incubation with MLCK and ATP. We found myosin thick filament assembly to be independent of the extent of 18,000-D light-chain phosphorylation when measured as a function of ionic strength. However, actin-activated Mg2+-ATPase activity of Dictyostelium myosin was found to be directly related to the extent of phosphorylation of the 18,000-D light chain. MLCK-treated myosin moved in an in vitro motility assay (Sheetz, M. P., and J. A. Spudich, 1983, Nature (Lond.), 305:31-35) at approximately 1.4 micron/s whereas phosphatase-treated myosin moved only slowly or not at all. The effects of phosphatase treatment on the movement were fully reversed by subsequent treatment with MLCK.

scholarly journals Roles of Inhibitors of Myosin Light Chain Kinase and Tyrosine Kinase on Cation Influx in Agonist-Stimulated Endothelial Cells

1997 ◽  
Vol 235 (3) ◽  
pp. 657-662 ◽  
Author(s):  
Reiko Takahashi ◽  
Hiroshi Watanabe ◽  
Xu-Xia Zhang ◽  
Hiroyasu Kakizawa ◽  
Hideharu Hayashi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Kinase ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain

scholarly journals Phosphorylation by casein kinase II alters the biological activity of calmodulin

1992 ◽  
Vol 283 (1) ◽  
pp. 21-24 ◽  
Author(s):  
D B Sacks ◽  
H W Davis ◽  
J P Williams ◽  
E L Sheehan ◽  
J G N Garcia ◽  
...  
Keyword(s):  
Light Chain ◽  
Cyclic Nucleotide ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Maximal Velocity ◽  
Intact Cells

Calmodulin is the major intracellular Ca(2+)-binding protein, providing Ca(2+)-dependent regulation of numerous intracellular enzymes. The phosphorylation of calmodulin may provide an additional mechanism for modulating its function as a signal transducer. Phosphocalmodulin has been identified in tissues and cells, and calmodulin is phosphorylated both in vitro and in intact cells by various enzymes. Phosphorylation of calmodulin on serine/threonine residues by casein kinase II decreases its ability to activate both myosin-light-chain kinase and cyclic nucleotide phosphodiesterase. For myosin-light-chain kinase the primary effect is an inhibition of the Vmax. of the reaction, with no apparent change in the concentration at which half-maximal velocity is attained (K0.5) for either Ca2+ or calmodulin. In contrast, for phosphodiesterase, phosphorylation of calmodulin significantly increases the K0.5 for calmodulin without noticeably altering the Vmax. or the K0.5 for Ca2+. The higher the stoichiometry of phosphorylation of calmodulin, the greater the inhibition of calmodulin-stimulated activity for both enzymes. Therefore the phosphorylation of calmodulin by casein kinase II appears to provide a Ca(2+)-independent mechanism whereby calmodulin regulates at least two important target enzymes, myosin-light-chain kinase and cyclic nucleotide phosphodiesterase.

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