Effects of mitogen-activated protein kinases on nuclear protein importThis paper is one of a selection of papers published in this Special Issue, entitled The Nucleus: A Cell Within A Cell.

2006 ◽  
Vol 84 (3-4) ◽  
pp. 469-475 ◽  
Author(s):  
Randolph S. Faustino ◽  
Delphine C. Rousseau ◽  
Melanie N. Landry ◽  
Annette L. Kostenuk ◽  
Grant N. Pierce
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Protein Import ◽  
Nuclear Protein ◽  
Muscle Cells ◽  
Inhibitory Effects ◽  
Permeabilized Cell ◽  
A Cell ◽  
Nuclear Protein Import

ERK-2 MAP kinase activation induces inhibitory effects on nuclear protein import in vascular smooth muscle cells. The mechanism and characteristics of this effect of ERK-2 were investigated. An unusual dose-dependent effect of ERK-2 on nuclear protein import was identified. At higher concentrations (1 μg/mL) of ERK-2, nuclear protein import was stimulated, whereas lower concentrations (0.04 μg/mL) inhibited import. Intermediate concentrations exerted intermediate effects. The stimulatory and inhibitory effects at the 2 different ERK-2 concentrations were observed in both conventional, permeabilized cell assays of nuclear protein import and with in situ microinjection of smooth muscle cells. The biphasic effects of ERK-2 on import were also found for the other 2 members of the MAPK family, p38 and JNK. RanGAP was identified by structural analysis as a candidate target protein responsible for mediating the effects of ERK-2. After pretreatment with high concentrations of ERK-2, RanGAP activity was significantly increased by ~50%. In contrast, low concentrations of ERK-2 significantly attenuated RanGAP activity. These results demonstrate that all 3 members of the MAPK family can alter nuclear protein import in opposite directions depending upon the concentration of ERK-2 used. RanGAP represents the MAP kinase target whereby nuclear transport can be stimulated or inhibited.

RanGAP-Mediated Nuclear Protein Import in Vascular Smooth Muscle Cells Is Augmented by Lysophosphatidylcholine

2006 ◽  
Vol 71 (2) ◽  
pp. 438-445 ◽  
Author(s):  
Randolph S. Faustino ◽  
Lyle N. W. Stronger ◽  
Melanie N. Richard ◽  
Michael P. Czubryt ◽  
David A. Ford ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Protein Import ◽  
Nuclear Protein ◽  
Muscle Cells ◽  
Nuclear Protein Import

scholarly journals RGS5 Attenuates Baseline Activity of ERK1/2 and Promotes Growth Arrest of Vascular Smooth Muscle Cells

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1748
Author(s):  
Eda Demirel ◽  
Caroline Arnold ◽  
Jaspal Garg ◽  
Marius Andreas Jäger ◽  
Carsten Sticht ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Genetic Ablation ◽  
Variable Expression ◽  
Arterial Blood

The regulator of G-protein signaling 5 (RGS5) acts as an inhibitor of Gαq/11 and Gαi/o activity in vascular smooth muscle cells (VSMCs), which regulate arterial tone and blood pressure. While RGS5 has been described as a crucial determinant regulating the VSMC responses during various vascular remodeling processes, its regulatory features in resting VSMCs and its impact on their phenotype are still under debate and were subject of this study. While Rgs5 shows a variable expression in mouse arteries, neither global nor SMC-specific genetic ablation of Rgs5 affected the baseline blood pressure yet elevated the phosphorylation level of the MAP kinase ERK1/2. Comparable results were obtained with 3D cultured resting VSMCs. In contrast, overexpression of RGS5 in 2D-cultured proliferating VSMCs promoted their resting state as evidenced by microarray-based expression profiling and attenuated the activity of Akt- and MAP kinase-related signaling cascades. Moreover, RGS5 overexpression attenuated ERK1/2 phosphorylation, VSMC proliferation, and migration, which was mimicked by selectively inhibiting Gαi/o but not Gαq/11 activity. Collectively, the heterogeneous expression of Rgs5 suggests arterial blood vessel type-specific functions in mouse VSMCs. This comprises inhibition of acute agonist-induced Gαq/11/calcium release as well as the support of a resting VSMC phenotype with low ERK1/2 activity by suppressing the activity of Gαi/o.

Thrombin induces endothelin expression in arterial smooth muscle cells

2000 ◽  
Vol 278 (5) ◽  
pp. H1606-H1612 ◽  
Author(s):  
Delphine Lepailleur-Enouf ◽  
Olivier Valdenaire ◽  
Monique Philippe ◽  
Martine Jandrot-Perrus ◽  
Jean-Baptiste Michel
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Mrna Expression ◽  
Protein Tyrosine Kinase ◽  
Muscle Cells ◽  
Transcriptional Level ◽  
Peroxisome Proliferator ◽  
Extracellular Medium ◽  
Map Kinase Kinase

Thrombin has been shown to stimulate endothelin release by endothelial cells, but the ability of thrombin to induce endothelin in nonendothelial cells is less well-known. Incubation of rat aortic smooth muscle cells with thrombin resulted in a stimulation of preproendothelin-1 (preproET-1) mRNA expression. This induction of preproET-1 mRNA expression by thrombin was accompanied by the release of immunoreactive peptide ET-1 into the extracellular medium. The synthetic thrombin receptor activator peptide (TRAP) confirmed ligand-specific receptor action to induce preproET-1 mRNA. Nuclear run-on analysis revealed that the transcriptional rate of preproET-1 mRNA increases twofold after 1 h of incubation with thrombin. In cells treated with thrombin, the half-life of preproET-1 mRNA was identical to that in untreated control cells. These results demonstrated that thrombin regulates endothelin synthesis at a transcriptional level but does not influence mRNA stability. Inhibition of protein kinase C (PKC) with selective inhibitors (chelerythrine and bisindolylmaleimide I) before thrombin stimulation failed to significantly inhibit preproET-1 gene expression. Inhibition of mitogen-activated protein (MAP) kinase kinase and protein tyrosine kinase decreased preproET-1 mRNA expression in thrombin-stimulated smooth muscle cells. Furthermore, addition of an activator of peroxisome proliferator-activated receptors-α (PPARα), fenofibrate, prevented the preproET-1 gene induction in response to thrombin. These results demonstrated that thrombin-induced endothelin gene transcription involved MAP kinase kinase rather than the PKC cascade in smooth muscle cells, which was repressed by PPARα stimulation.

Modulation of smooth muscle contraction by sphingosylphosphorylcholine

1995 ◽  
Vol 269 (3) ◽  
pp. G370-G377 ◽  
Author(s):  
K. N. Bitar ◽  
H. Yamada
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Intracellular Signaling ◽  
Calcium Release ◽  
Muscle Cells ◽  
Smooth Muscle Contraction ◽  
Mitogen Activated Protein Kinase ◽  
Maximal Response

We have investigated the effect of sphingosylphosphorylcholine (SPC), a synthetic product that was implicated in the sphingomyelin cycle, and have assessed its role in intracellular signaling. SPC induced a dose-dependent contractile effect of smooth muscle cells isolated from the rectosigmoid of the rabbit. Maximal contraction occurred at 10(-6) M. The response started early, 25.4 +/- 6% shortening at 15 s, peaked at 30 s (32.5 +/- 2%), and remained sustained at 8 min (30.0 +/- 3.5%). Preincubation of the cells with thapsigargin had no effect on contraction induced by SPC. The response to a combination of threshold concentrations of inositol 1,4,5-trisphosphate (IP3) and SPC was additive and was significantly different from the maximal response elicited by each agent alone. SPC also induced activation of mitogen-activated protein kinase (MAP kinase). This study demonstrates that SPC is important in cellular signaling of gastrointestinal smooth muscle cells through a mechanism that is independent of IP3-sensitive calcium release and probably through activation of a protein kinase C-mediated activation of MAP kinase.

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