scholarly journals Mitogen-activated protein kinases (MAPKs) are modulated during in vitro and in vivo infection with the intracellular bacterium Burkholderia pseudomallei

2017 ◽  
Vol 36 (11) ◽  
pp. 2147-2154 ◽  
Author(s):  
R. V. D’Elia ◽  
R. J. Saint ◽  
S. L. Newstead ◽  
G. C. Clark ◽  
H. S. Atkins
Keyword(s):  
Protein Kinases ◽  
Burkholderia Pseudomallei ◽  
Intracellular Bacterium ◽  
Mitogen Activated Protein Kinases ◽  
Mitogen Activated Protein

On the mode of action of thrombin-induced angiogenesis: thrombin peptide, TP508, mediates effects in endothelial cells via αvβ3 integrin

2004 ◽  
Vol 92 (10) ◽  
pp. 846-857 ◽  
Author(s):  
Nikos Tsopanoglou ◽  
Matthew Papaconstantinou ◽  
Christodoulos Flordellis ◽  
Michael Maragoudakis
Keyword(s):  
Endothelial Cells ◽  
Protein Kinases ◽  
Cell Attachment ◽  
Growth Factor Receptor ◽  
Αvβ3 Integrin ◽  
Mitogen Activated Protein Kinases ◽  
Rgd Sequence ◽  
Mitogen Activated Protein

SummaryIn a previous report we have presented evidence that thrombin interacts with αvβ3 integrin in endothelial cells at the molecular and cellular level. This interaction was shown to be of functional significance in vitro and in vivo and contributed to activation of angiogenesis by thrombin. In the present study, we have used a synthetic thrombin peptide, TP508, which represents residues 183 to 200 of human thrombin. This peptide lacks the catalytic site of thrombin but contains the thrombin RGD sequence. Immobilized (surface-coated) TP508 peptide, like thrombin, supported αvβ3 integrin-dependent endothelial cell attachment and haptotactic migration. These effects were specific (a scrambled TP508 peptide was without effect), and dosedependent. The RGD sequence was essential since a modified TP508 peptide, which contained RAD sequence instead of RGD, was inactive. Immobilized TP508 peptide stimulated phosphorylation of mitogen-activated protein kinases and focal adhesion kinase, the signal transduction pathways characteristic for integrin activation. On the other hand, TP508 peptide, when in solution, did not mimic other thrombin-promoted angiogenic effects, such as that of activation gelatinase A, upregulation of expression of vascular endothelial growth factor receptor mRNA or prostacyclin PGI2 release in endothelial cells. On the contrary, soluble TP508 acted as an antagonist for the aforementioned effects of thrombin. TP508 peptide inhibited these thrombin-induced effects through a RGD and α. vβ3-related mechanism. The antagonism with thrombin or thrombin receptor activating peptide was specific and involved at least in part mitogen-activated protein kinases activation. These results point to the importance of RGD sequence of thrombin in mediating effects on endothelial cells and angiogenesis.

scholarly journals Mitogen-activated protein kinases are carbon dioxide receptors in plants

2020 ◽  
Author(s):  
Hanna Gałgańska ◽  
Łukasz Gałgański
Keyword(s):  
Protein Kinases ◽  
Stomatal Response ◽  
Mitogen Activated Protein Kinases ◽  
Environmental Signals ◽  
Know How ◽  
Mapk Signalling ◽  
Mitogen Activated Protein ◽  
Upstream Regulators

AbstractThe amount of CO2 in the atmosphere is increasing continuously in the industrial era, posing a threat to the ecological balance on Earth. There are two ways to reduce elevated CO2 concentrations ([CO2]high): reducing human emissions or increasing their absorption by oceans and plants. However, in response to [CO2]high, plants diminish gas exchange and CO2 uptake by closing stomata. Surprisingly, we do not know how plants sense CO2 in their environment, and the basic mechanisms of the plant response to [CO2]high are very poorly understood. Here, we show that mitogen-activated protein kinases (MAPKs) are plant CO2 receptors. We demonstrate that MPK4, a prominent MAPK that is known to be involved in the stomatal response to [CO2]high1–3, is capable of binding CO2 and is directly activated by a very low increase in [CO2] in vivo and in vitro. Unlike MPK4 activation by infections4, stress and hormones within known MAPK signalling cascades, [CO2]high-induced MPK4 activation is independent of the upstream regulators MKK1 and MKK2. Moreover, once activated, MPK4 is prone to inactivation by bicarbonate. The identification of stress-responsive MPK4 as a CO2 receptor sheds new light on the integration of various environmental signals in guard cells, setting up MPK4 as the main hub regulating CO2 availability for photosynthesis. This result could help to find new ways to increase CO2 uptake by plants.

scholarly journals Phosphorylation of MafA Is Essential for Its Transcriptional and Biological Properties

2001 ◽  
Vol 21 (14) ◽  
pp. 4441-4452 ◽  
Author(s):  
Sofia Benkhelifa ◽  
Sylvain Provot ◽  
Eugène Nabais ◽  
Alain Eychène ◽  
Georges Calothy ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Leucine Zipper ◽  
Biological Properties ◽  
Erk Pathway ◽  
Mitogen Activated Protein Kinases ◽  
Mitogen Activated Protein ◽  
Basic Region

ABSTRACT We previously described the identification of quail MafA, a novel transcription factor of the Maf bZIP (basic region leucine zipper) family, expressed in the differentiating neuroretina (NR). In the present study, we provide the first evidence that MafA is phosphorylated and that its biological properties strongly rely upon phosphorylation of serines 14 and 65, two residues located in the transcriptional activating domain within a consensus for phosphorylation by mitogen-activated protein kinases and which are conserved among Maf proteins. These residues are phosphorylated by ERK2 but not by p38, JNK, and ERK5 in vitro. However, the contribution of the MEK/ERK pathway to MafA phosphorylation in vivo appears to be moderate, implicating another kinase. The integrity of serine 14 and serine 65 residues is required for transcriptional activity, since their mutation into alanine severely impairs MafA capacity to activate transcription. Furthermore, we show that the MafA S14A/S65A mutant displays reduced capacity to induce expression of QR1, an NR-specific target of Maf proteins. Likewise, the integrity of serines 14 and 65 is essential for the MafA ability to stimulate expression of crystallin genes in NR cells and to induce NR-to-lens transdifferentiation. Thus, the MafA capacity to induce differentiation programs is dependent on its phosphorylation.

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